I've leveled all roles. With DPS roles it's just important to use your leve allowances and fill out that hunting log. Can help as well to have a decent FC or an LS or two that you can enlist low level help from. Basically just make good use of the 20ish minutes or so you might be waiting for that queue. Heck sometimes I switch to another low level class to work in THAT Hunting Log or do leves for THAT class. The class that's my primary focus gets all my low level and guildhest roulettes as well.