Lamp def. gives good tips.
The way I worked drum patterns when I first got my mpc was using 2 bars, I didnt worry about setting a tempo too much and set timing to OFF. On track 1, I would only lay snare hit at whatever "tempo" I was feeling (less is more when learning here). It's important to like the feeling of snare hit while loopin cause it will dictate where u are gonna drop a kick drum. On track 2, while snare was loopin I began to add the kick(s) and listen to loop, if I wasn't happy w/ flow I'd erase the kick I just added (or whole track) and try again and try again and try again. My first patterns were extremely simple:
thump...snap...thump...snap...thump...snap
just to get a "groove", then using same technique I moved to something like:
thump..thump...snap...thump..thump...snap
And from here just practiced and got more complex, even tho I still like using simple patterns sometimes. I guess I learned backwards from the tip Lampdog gave, but when I finally turned timing ON and found right tempo, I def. knew what kinds of grooves I was looking for and it tightened up my patterns without sounding too robotic.
I don't know, hope it helps.