THIS is a BnB? I been practicing this for awile and I still can't get it down. I haven't really done much with other character's BnB's, but are they all this ridiculous?
For perspective, this is an optimized BnB for damage, not taking into account the difficulty. This BnB does use a lot of Double's combo mechanics that take practice to execute reliably (linking s.MK off of Flesh Step and using Cilia Slide). Rest assured, there are plenty of easier ones, you just sacrifice damage. If you don't know how to do Barrel Loops, they are the best beginner Double combo! Here:
c.LK s.MKx2 s.HK /\
j.LP j.MK j.HK xx MK Item Crash \/ (this is the barrel where it gets its name!)
s.LK (the s.LK is a 5 frame link I believe, and the hardest part of the combo) s.MKx2 s.HK /\
j.LK(1 hit) j.MK j.HK xx MK Item Crash \/ (another barrel! almost like you're LOOPING it!)
s.LPx2 s.MKx2 c.HP xx HK Hornet Bomber xx Bandwagon Rushdown
This is a great beginner combo because it works without OTG, works off her grab, and is universal with the exception of Big Band. If you have any questions of want something else, feel free to ask. c:
Edit: You can also check out this thread for more combo ideas:
http://skullgirls.com/forums/index.php?threads/guns-n-barrels-double-combo-thread.182/
Everything there should still work in the Beta version of the game. Double is a great free style combo character since she isn't overly reliant on OTGs, so learn some of her basic patterns and you'll be able to effectively combo with her in no time.