If you have a level 50 friend, they can help you level up to about 12-15 just by you running around tagging mobs, then they kill it. Grab stuff high enough to get a chain going. Once your up to 12ish, you can go to aelport for fates to 16. Once you are 16 you can start doing low-level roulette as well as guildhest roulette. As DPS, you queue times can get quite insane, so try doing fates/guild leves/leve quests while waiting on your queue.

Since I've not been in a rush to level my other classes, just doing a low level roulette and the guildhest roulette has been the majority of the experience for my alt classes.