XP Potions: The Elixir of Rapid Mind and Elixir of Ancient Knowledge no longer drop. They can be bought on the AH still but are way to expensive for it to be worth it. The Excess Potion of Accelerated learning is available from your garrison quartermaster but only works for level 91 to 99. As of Patch 8.1 you can also buy the 10% XP Potion Draught of Ten Lands.
There are other in-game guides out there such as Xcelerated, but it doesn’t even come close to what Dugi and Zygor offer.  Although I’m obviously a fan of Dugi Guides, I have given a fair side by side comparison of each guide, based on facts and what is offered by each. I’ve included many screenshots to give you an idea of how each guide looks and works within the game. I will do my best to keep this as up to date as possible, with price changes, guide updates etc as I know how annoying it is reading outdated reviews.

I highly recommend actually staying in the 20-60 range zones until you ding 62. The reason for this is that despite getting a slight penalty in experience for being over-level, the advantage of having flight will more than offset this. That, and WOTLK and TBC zones are the slowest part of the leveling process. Minimizing your time there as much as possible is worthwhile.
Meanwhile, in Zandalar, the Horde seeks to earn the trust of King Rastakhan so they can use his legendary Golden Fleet against the Alliance. To this end, they assist Rastakhan and his court in dealing with local threats in Zuldazar, fight maniacal Blood Trolls in Nazmir, and face off with serpentine Old God cultists in Vol'dun. Throughout their journey, the Horde gradually learns about an eldricth being known as G'huun, an artificial Old God accidentally created by the Titans and the patron deity of the Blood Trolls. The Blood Trolls and the Faithless Sethekk seek to free G'huun from his prison of Uldir so they can use him to rule Azeroth, and to this end they resurrect G'huun's champion, the C'thrax Mythrax, to destroy Uldir's seal. Rastakhan's own chief adviser, the prophet Zul, is revealed to be the Blood Trolls' secret leader and launches an armed revolt against Rastakhan. With the Horde champions' help, Rastakhan is able to defeat Zul and his forces, but not before Mythrax destroys Uldir's seal.
While leveling, try to make use of the new Battle of Azeroth experience gem, Insightful Rubellite, which gives you +5% experience. Equipping one of these requires a socket in your gear, so try to hold on to a piece of Legion gear with a socket or acquire one of the Legion Legendary rings since every class has one. Each of the rings includes a socket. You can acquire one of these rings rather easily by doing World Quests in Legion zones and acquiring 1,000 Wakening Essences that can be used to purchase a legendary ring in the Legion version of Dalaran.
A "stat squish" and "item squish" was implemented to lower the numbers used in the game, e.g. a legendary item previously with a level of 1000 reduced to 265. Unique class-specific buffs are added back, i.e. mages' Arcane Brilliance and priests' Mark of Fortitude. Titanforging—a random event that raises the initial item level of an item gained via drops or rewards—is still in the game; however, if the item is one of those affected by the Heart of Azeroth, then that item cannot be titanforged. 

If you’re a returning player, consider paying for a month’s worth of playing time—a mere $15—and using the game’s newer Class Trials to see if you still have that spark for higher-level play. While you can also go the “Starter Edition” route for a free, limited romp through Azeroth, you might need a little more than the newbie zones to help you decide whether you want to play through the game’s latest expansion.
Update: The reason for less experience from gathering is due to how Blizzard revamped professions and broke them down by expansion. In order to get full exp from gathering you'll simply need to find a profession trainer for the relevant expansion. (WoD you just mine or herb the first one ypu come across and the game gives you a scroll for learning WoD gathering).
This includes the “Tides of Vengeance” campaign missions, which continue the War campaign introduced when the expansion launched. Two new island expeditions called Jorundall and Havenswood were also added. Weekly quests also require less Azerite than they did in the past, Mythic and player-versus-player islands award more Artifact power, and new vendors were made available.
Similar problems have risen in the leveling system, which automatically scales to the player’s level and equipment. For the most part, you’ll vaporize enemies more quickly as you gain power, but there are some weird dips. Many players complained they felt less powerful at level 119 than at level 110, a problem I experienced myself. And world PvP remains a strange and whacky world where level and class balance issues make wins and losses feel destined instead of earned.
Each of those modes existed long before this latest expansion; raiding is a basic concept in MMOs, and Mythic+ was added in World of Warcraft’s last expansion. The problems with Battle for Azeroth’s endgame come from the systems it adds, which most often artificially gate progress where most of the fun can be found. If raids and Mythic+ are the carrot, we’re about to talk about the stick.
Elixirs serve the same purpose as Flasks, but the buff expires if you die. You'll only use these between 1-70, generally speaking, until you can start buying Flasks which persist through death. Try not to die, and carry extras just in case. If you can't find an Elixir with the stat you want, look under scrolls, since they count as battle or guardian buffs as well.
Players who were around during Mists of Pandaria might recall a dungeon mode called Scenarios, which involved teams of three players instead of the traditional five. Island Expeditions bring a similar feel, with groups being tasked with plundering treasure off various islands. Your team faces off against other players or AI-controlled characters from the opposing faction and whoever can collect the most treasure, or "Azerite," wins.
Level with a pet if you can because it will help keep you safe. If your pet is tanking all of the damage from the enemies you’re fighting, you won’t have to. The other reason is that pets are easier and cheaper to heal than you are. If you don’t have a pet, make sure you know how to use your defensive abilities. You can’t level quickly if you are dying all the time.

Unlock all of the traits in your Azerite Armor. Each piece of Azerite Armor — which can be head pieces, chest pieces and shoulders — has three traits that you can unlocked with Azerite Power, or AP. AP is something that most types of endgame activities will give you in Battle for Azeroth, but some are more effective than others. In the first few weeks, you’ll want enough AP to unlock all of the traits on all of your armor, however much that may be.
And if anything, this addon is more legit than an addon such as auctioneer. You can effectively set auctioneer up to auto purchase or at least auto prompt you to buy out items within a price range you specify - that's far more automation (rescanning the AH once per second, automatically informing you of deals with a buyout option button ready to be clicked, etc) than Zygor's does.
Incursions are a new world content activity that are unlocked when one character has unlocked World Quests. This feature is unlocked account-wide meaning that all characters on that account can access Incursions even without being Level 120. This provides for a lucrative experience acquisition method that is available in a similar pattern to what Legion Invasions offered with nearly an entire level earned by completing an Incursion series which involves four World Quests and one mini-scenario at the end. These also grant item level 370 weapons and Azerite armor, so they should be done any time they are up. Incursions follow a similar schedule to Invasions and are available for 20 hours once they are initiated.
Drustvar is far and away the hardest Alliance zone, which is exactly why you want to do it first. If you have legendary items, they’ll still be usable, and if you don’t, this zone will still be easier early on than it will be later. Drustvar is also extremely fast and will let you jump out ahead of your competition in other zones, which means fewer players around to take your quest objectives.
Some dungeons are also much better than other. Some take a long time to finish and some are quick. Some have few quests and others have many. The ideal dungeons have a lot of quests and are quick to finish. If you are sent to a long dungeon that you have already completed, you can leave but you won’t be able to enter a new dungeon in 30 minutes. Dungeons like the Stockade are super quick, so it will still be good XP if you are sent here more than once.
REDISCOVER AZEROTH AS NEW ALLIED RACES – Take a new form for your adventures as new playable Allied Races. Embark on a quest to earn the favor of the Lightforged draenei, Highmountain tauren, Nightborne, Void elves, Dark Iron dwarves, and Zandalari trolls to unlock each race and add their strength to your faction. Create a new character and complete the full leveling experience to earn a distinctive Heritage Armor set.

Island Expeditions:[5] 3-Player co-op with optional 3v3 gameplay. Players will explore uncharted isles across the Great Sea. There is azerite and other unclaimed resources bubbling to the surface that is highly sought by both factions. Complete varied and dynamic objectives with a large variety of challenges to overcome. Race against advanced AI opponents designed to thwart players using tactical and strategic moves that consistently change. Optionally, players can choose to race against other players, creating a 3v3 PvP environment. 
I guess maybe I'm familiar enough with it to just slam it out. I don't recall any low droprate quests as bad as 5%. Although Blizzard has been screwing with stuff lately. Do you remember which quest it was? A lot of those can be skipped if they're too tedious. Like literally ALL the quests on that little island in the NE corner of the map with the ghost pirates underwater and the dragon whelps.
Anyway, however you choose to get to the addon's menu, choose guide list and then pick the zone you want to quest in. There are some zones that will autoselect based on quests in your log, but not all guides or all quests are set up that way. (If you don't want to switch to a guide that auto-pops up choose "not now" or "never") As you can see in the screenshot, there are various categories of guides. Most max level content (such as Argus) is found in Achievements rather than leveling.
Island Expeditions are three-man scenarios that pit the team against three enemies using what Blizzard calls “advanced A.I.” That means the enemies will act more like players, pursuing goals proactively and filling class roles. The expeditions take inspiration from action RPGs, with randomized areas that mix up the experience each time. Players’ main goal will be obtaining resources more quickly than their foes, and expeditions should last 15 to 20 minutes. While primarily meant for PvE, there is a PvP mode that replaces the opposing A.I. with teams from the enemy faction.
Most heirlooms only work in a limited level range in their default form and must be upgraded to work at higher levels. That costs gold, and you’ll need around 30,000 gold to outfit yourself with a fully upgraded set (counting only those that give you bonus experience). You may need to spend some time on a boosted character to acquire the gold you need to outfit another character with heirlooms, but it’s well worth the effort.

Hey! Just came back from the game, looking to play bfa but i had no idea what to do when i logged on. It was all a bit confusing and i know nothing about the current content. So after some frustration i bought zygor again (haven't used it since cata ..) and i do currently feel more comfortable. I'm following the guides from the 'suggested' tab in zygor but i'm just really unsure if what i'm doing is even relevant. I know the end of the expansion is coming so i'd hate to waste my time. OK i will list the things it's been telling me to do.
A "stat squish" and "item squish" was implemented to lower the numbers used in the game, e.g. a legendary item previously with a level of 1000 reduced to 265. Unique class-specific buffs are added back, i.e. mages' Arcane Brilliance and priests' Mark of Fortitude. Titanforging—a random event that raises the initial item level of an item gained via drops or rewards—is still in the game; however, if the item is one of those affected by the Heart of Azeroth, then that item cannot be titanforged.
Players’ relationships with the NPCs around them have been hit-and-miss over the years. One of the original issues with Thrall, the Horde’s original Warchief, is that players began to refer to him as “green Jesus,” because of how infinitely powerful and infallible he was. But he’s been gone since the Warlord of Draenor expansion, and with the death of Varian Wrynn and Vol’Jin at the start of Legion, the old guard hasn’t been there to guide players the same way as it used to be. 
×