I tend to use loops already made or i use single hits and pass the loop into wav.
Then i use warp and i mess with the rythms, use reverbs, distorts and watever fx you like, it all depends of how you want it to sound.
Rex files are wicked in Cubase, just mute some hits and change the order...
Wav is the best way, you can play more with it, just do the single hits then do a loop of it.

Good Luck, dont be scared to experiment dont follow the usual rules.....