One of the most popular ways to level a character currently available is boosting them in dungeons on the Remix: Mists of Pandaria. As this method of leveling requires two accounts, a solution players often used was to use a free trial as their second account to level characters on their main account, as they benefit from the insane scale low level characters get.
In MoP Remix, scaling is everything — And scaling is even more insane for lower level characters. Trial accounts are hard locked at a maximum cap of level 20 (and the NPCs that lock experience gains are inacessible on the MoP Remix phase), so Trial accounts are able to keep characters at lv20 and continuously benefit from the power increase from Threads.
A lv20 character with full damage gems and a decent number of threads is able to solo Heroic dungeons with ease, allowing them an easy time boosting other characters. Learn more how to level the quickest in MoP Remix by reading our previous new post!
Best Method to Level Characters Quickly in MoP Remix — Up to 40k Bronze / Hour