Isle of Quel'Danas: Special mention. At lvl 70 you can start doing the dailies here. Despite not being able to fly, the quest density is VERY high. I recommend hitting this every reset if you spend more than 24 hours REAL time(not /played)in the 70-80 level range. In fact, if you're doing a monk and only logging in once each day anyway, IQD WILL be your best exp/h for this level range.
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.
This kind of storytelling comes with problems, ones that players have been facing since the early days of the silent video game protagonist. Players in World of Warcraft have so much agency and choice when it comes to their own characters and how they build them. But despite their importance to the world itself, they can do nothing to change its story.
Set sail for the previously unmapped isles of Azeroth. Battle in groups of three as you race against cunning rival intruders—or enemy players—to collect the island’s resources. Constantly evolving challenges await as you traverse frozen landscapes near Northrend, open the gates of an abandoned Gilnean castle, navigate a war between elementals and more. Tides of Vengeance adds two new Island Expeditions to the mix and two new random events, as well as updated rewards.
Dugi’s leveling guide is the leveling addon I’ve always used to level as fast as possible. It will show you where to go and what to do in-game, speeding up the leveling process. This is optional though, as the game already does a pretty good job at showing you where to go at all times. The addon does, however, come with a couple of other nice features and perks.
Most classes in World of Warcraft start at first level, but Death Knights and Demon Hunters are exceptions. They start at level 55 and 98, respectively. This alone can shave a huge chunk of time from your leveling experience. Of course, it only works if you want to play a Death Knight or Demon Hunter, but they’re both solid classics that can dish out damage or tank in a group.
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.
Stormheim is the zone you want to start it. For some reason Legion treasures are not worth any experience like they are in WoD...except in Stormheim. I haven't been able to find out any reason for this, and it's possible it may get fixed/nerfed at a later date. But for the time being you REALLY want to jump from treasure to treasure to augment your quest experience.