Heres what you do: 1st. Get the char you want to power lvl out of the starter zone.(It helps the process if the char that is to be pwrlvld has a range attack). 2nd Get a lvl 50 out to the starting zone where the new char is waiting. 3rd The low lvl char goes around attacks a target, soon as he does any dmg to the target. The lvl 50 can kill it, or them. and the low lvl char will get all the xp for that kill. As thow he killed him self and along.(You can not be in a party to do this)
Using this method + 100% lvl potions was able to lvl my buddy from lvl7-49 less then 48hrs played
I was using a cleric spec sent/inq/cab. for dots and aoe
Takes only a try or two to get it down good luck have fun