When I leveled MNK recently, I just got a bunch of my LS mates together and did levequests. With 5+ people in the PT we were able to burn through leves very quickly and leveling was a breeze. I am sure there's other things you can do like PL'ing, but that is pretty lame imo. Leveling the legit way is already fast as heck... you can easily get from 1-50 in a week without getting a PL at all.
Edit I should mention that I soloed pug from 1-15; did Levequest parties from 15-40 and then Zaharak PT from 40-45~ish then Natalan from 45-50.
Edited, Apr 7th 2012 3:09pm by StateAlchemist
____________________________Humankind cannot gain anything without first giving something in return. To obtain, something of equal value must be lost. Data Center: Primal; Server: Ultros; Free Company: The Kraken Club; Grand Company: The Maelstrom; Chocobo: Kweh