I normally scribble a lot to get what few good poses I have managed to draw.
The one you did last contest had a lot of movement though!
Try playing the game your creature is in might help you think of poses, or read an action filled comic (or watch an action filled animation?) If you do this make sure you watch or read something new, because it'll probably help get your brain thinking better than something you're familiar with.
I dunno how other people do it but I rely a lot on retracing/refining what I've drawn for real media, or heavy layer use in digital. (sometimes I do both).
For digital art I'll draw whatever pose idea I have first without a ton of regard for how right it looks, just to get it down somewhere. Then isolate whatever bits look right, and make a new layer to do some redlining and draw the basic skeleton out. Then I clean it up and see if it looks better (repeat till you're satisfied).
Sometimes I end up having to redraw whole areas over and over again, but normally bit by bit it comes together. It's also really good drawing practice.
Maybe this won't work for you, but I know that it makes a pretty big difference in the quality of art when I do this and when I don't. So you could try it I guess, it's not as time intensive as it sounds either (knowing most of us are pretty strapped for time).