I wont be able to actually get on until 4 because of school reasons, but i have a level 52(? i havent checked in a while) gaige and i would love to get that number up to 72 or even in the OP levels. same with my level 72 Maya. Thanks!
Grab a morningstar and use the glitch to farm tender snowflake on repeat. You will get a lot of legendaries, which is great too. It took me about 3 days of farming him to get my gunzerker and zero from ~50 to 72. If you are trying to level one up and you have one character at 72 already, use 2 controllers, make a mule account, level the mule to 72 (marcus glitch in sanctuary), beat the game until you get to sanctuary in UVHM on your mule and then do the marcus mission glitch with your mule on your main account. I have found that a gunzerker with 2 rapid infinities works best as a mule.
You will need to plug both controllers directly into the console and tape the triggers on the mule and tape the left stick on the character being leveled.
Although this method takes a while, you will have a mule to power level any other characters on your main account.