Easiest way to level up when starting out:
Ask some high level guys to join a team with you so you share the experience they earn.
Heck, if you have a strong friend, ask them to kill some baddies for you. I mean they won't get killed since they are so strong, so it won't be a problem for them to help you a little. Then when you've gotten to a high enough level, you can kill them yourself.
I find that the "asking friends" trick works the best. Ask them for spare items, to help with experience, etc. I helped people gain exp when the housedungeons first came out, because I was the only one that got through it extremely fast.
