First get to a high enough lvl that u can fight within a range of 25-35 range players. once you are at that lvl you can gain levels as quickly as a noob.
Step 1: Gain access to the temple of the three winds
step 2:find a team that has most members equal or lower level than you
step 3:make sure that your team is large enough so that u can kill multiple monsters at once.
step for go into the temple and start gang raping the monsters if you and your team are good enough you can gain lvls in 5 minutes.