My sirens level 42. trying to figure a way to get this thing up to 50 faster. flesh-stick didnt work, i suppose they patched that.
you could do the Siren's invincibility glitch to make two other players (in a 4 player match) invincible and then every time they "die" (which they immediately pop back up from) you get 100 XP. In a typical 2-3 hour session, farming bosses and running levels you could probably get a hundred thousand xp. Combine that with the XP you'd be getting from bosses and enemies...
XBL GT: Ki11er Six (ones instead of L's and a space between the two words) Treasure Room glitch on Borderlands 2: http://www.youtube.com/watch?v=wuvwzTuUhqc
The best, active, method is to use the repeatable tier 3 bar brawl in Pete's bar. You can grind out volcanic rakk if you prefer, but the bar is the best way, really.
Words of wisdon! Not that fast or easy, but it's funny, legit, and your gonna be proud of you, developing your siren as a man (woman?). And doing this way, you're gonna reach level 50 rich with torgue tokens - four or five legendaries guaranteed.
Try farming bunker.Worked for me.Of course the trek to him is horrendous.
If you're farming Bunker, you only need to make this run once. After you defeat it, you can exit to Thousand Cuts and then turn around to go right back into The Bunker, and it will be there to fight again.