Leve quests. For a party with a friend(s) that has a level 60 character(s), then go to a zone that is your level...Aleport-lvl16, Costa-lvl30, ect.

You initiate the leve and they go smash the mobs and do the objectives. When they are done you turn in the leve and get the exp. Easy peasy. You don't even need to leave the leve quest giver's side either.