It's not an enchantment, but you should buy or craft an iLVL 100+ belt, gloves, or boots with a gem socket for use with the new 5% bonus experience gem: Insightful Rubellite. I used a vendor-bought belt from the legacy valor vendor in Orgrimmar, since it was convenient and met the minimum ilvl bonus. Keep these in your bags until you can equip them, which should be just in time for treasure collections in WoD content. I didn't ever replace the belt until I dinged 110, since I didn't feel the stats from later upgraded belt drops made enough of a difference to outweigh the 5% bonus. This is explained below, in the WoD treasure section.
The WoW token is very simple: You pay Blizzard $20 for a token, and then you can sell the token on the in-game auction house. A player with gold can buy a token and redeem it for a month of WoW subscription time or for $15 of Battle.net balance, which is like a gift card credit that can be redeemed in WoW or other Blizzard games such as Hearthstone and Overwatch. You get their gold; they get your cash, or at least most of it.
As always, I will monitor and update this guide as new information comes in. If I've gotten anything glaringly and completely wrong, just tell me with as much data as possible. The idea is to find the fastest possible leveling method, NOT to argue about how good or bad individuals are. If you have hard data, post it! If you have an idea, let the thread know so we can test it!
Enchants. I honestly wasn't 100% certain which enchants were best, since scaling has screwed up a lot of things. IMO, just pick the enchant for each armor slot that has the highest bonus without level restrictions. The exception is that you'll definitely want Mark of the Hidden Satyr for your neck piece, and probably Elemental Force for your weapon. Both of these proc consistently and strongly across all levels.
Congratulations on reaching Level 120! Now that you have hit Level 120 we recommend looking at our Easy mode page and Talents section to learn how to play at max level. To get yourself prepared for the end-game content ahead, we strongly recommend this Battle for Azeroth Raiding Lexicon/Spreadsheet by Medivh. It is a gold trove of information that will help you when gearing up in Battle for Azeroth and more.
I remember time when I was at teenage and I used to spend real money for wow gold from some suspicious "hacker" site from China or Korean what ever(note: I didnt spend much). And now I have realized how foolishly I did even I didnt about real money problems in there. Now that I have grown up I have also realized that I was one of those that caused playing problems for those young boys, that they had to play like 24/7 to farm gold for us lazy people.
The older brother of this potion originally came about in Cataclysm as the Potion of Treasure Finding, and is actually one of the best ways to make money. Since most Pandaria mats are constantly farmed, they usually sell for less than the Cataclysm mats. This makes using this form of the potion more effective for making gold. Not to mention that creatures die faster to level 90s since they were made for the previous expansion, making farming the treasure chests that drop rather easy.
To give you some perspective I leveled both a LF Ret Paladin and BE Rogue (so one started from level 20 and the other from level 1). I focused on getting the achievements I was missing for the Loremaster, so not the most efficient route by any means. I was using full enchanted heirlooms (minus the ring) and the WoW-Pro addon though, as well as having War Mode turned on all the way.
Something to keep in mind as well is that this will make enchanting materials more valuable, since it is likely most players will now simply scrap their boe greens instead of getting them disenchanted. Also redundant dungeon/raid gear can be scrapped rather than traded to the (guild) enchanter in the run. Less stuff gets disenchanted, meaning there will be less ecnhanting materials, meaning their value will rise. All the more reason to DE rather than scrap as an ecnhanter.