Hey dude, it really depends on a number of things. You haven't told us a lot of information about your account and plans.
Question 1 : Are you a member?
Question 2 : Will you be questing for new weapons?
Question 3 : Will you have a good budget for armour
Personally, for the lower levels I'd just do quests and kill shit along the way, as once you get to 40/40/40, you can start doing slayer, and do that until maximum melee. It's not the fastest method, but it's the most rewarding IMO.