Power leveling is the term used to describe the process of leveling a character as rapidly as possible with the least amount of play time. It can be used from any level up to level cap. Contrary to what many believe, efficient power leveling does not require endless hours of grinding. The best methods of power leveling involve doing many quests in an orderly fashion.
Power leveling is the process of handing over your character to another player (usually it's a seasoned WoW player), who then gets your character to the highest level possible in the shortest amount of time. In essence, someone else does all the hard work for you so that you don't have to waste your time by leveling the character/s yourself. And as with most other MMORPGs, there are a lot of players who offer such power leveling services for World of Warcraft.
Excess Potion of Accelerated Learning: Acquired in your Garrison (part of the Warlords of Draenor expansion), this gives you a 20-percent bonus to experience from killing monsters and finishing quests. It lasts one hour, but you can buy it multiple times and use it back-to-back. Alliance players buy it from Sergeant Crowler, horde players buy it from Sergeant Grimjaw. Does not work above level 99.
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.