Heirlooms are special pieces of armor that level up with your character, so they have stats that are always respectable for your character’s level (up to level 110). Heirlooms that fit the head, shoulder, chest, legs, and back armor slot offer an experience bonus. The total bonus is 45 percent if you have them all. It’s also possible to acquire a ring that adds another 5 percent, but you must win a fishing contest acquire it, and that can take some time.
For collecting artifact power to level up your Heart of Azeroth necklace, island expeditions are unbeatable. There’s a weekly Azerite goal that you need to meet through the expeditions, and when you do, you’ll be awarded 2500 artifact power. There’s a small chance that you’ll get weapons from completing expeditions too, but they’re not a reliable source of gear.
Heirlooms: Heirlooms are the best source of bonus XP for leveling. All slots can be gotten pretty easily now, except the rings. The time you need to spend to get the rings if you haven’t gotten a level 3 shipyard in WoW is way too long, so getting the rings is generally not worth it. Having all your heirloom gear will boost XP by 55%. Generally, you want heirloom gear with crit on for leveling as you want to kill mobs in a few hits as possible
Once you reach an Alchemy skill of 475, you may begin a quest to learn one of three specializations: Potions,Elixirs or Transmutations. Being specialized gives you a chance to create an extra 1 to 4 (for a total 5) items while crafting in the field you have selected. For example, a Master of Potions may be able to craft more than one [Super Mana Potion] for the same material cost as one.
For reference, my previous best time abusing Method-0 in 7.3.5 was 32.4 hours(as show in the old thread). A difference of just over 8 hours; which isn't all that bad, all things considered. And I believe I made several errors along the way, which could be cleaned up in future runs. I believe that that gap could be significantly closed by using a monk's bonus, but I hate playing monk...so...yeah. YMMV