I also wanted to note that a lot of users, I found on the Web claimed Dugi’s Guide to be faster.  However, all these users had either used Zygor Guides for very little time or had not used it at all.  I have to give a point to each Dugi’s Guide and Zygor Guides as they both deliver a great lvling speed.  For all you Dugi’s guide users out there who really feel that Dugi’s Guide is faster, I will give Dugi an extra  point.  If there really were a difference, it wouldn’t be by much.
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.
I just leveled this char in about 2 days played time with a few hours of it being afk in cities.What I did was run every single dungeon one time and do quests while waiting in queue.That way you don't get bored and the experience gain is great.Works particularly good between 60 and 90. WoD is a piece of cake if you just have flying and Legion is questing + doing the per zone dungeon for the 100k xp quest.
If you're looking for simple, just get actionator. Set it to undercut everything you post for 1c and alt click from your bags. It will place the item on the ah window, do a scan for that item and autoset the price for how much you told to undercut (you can change it accordingly if you feel like it). It will remember if you do stacks for which items and replicate it everytime.