In the past, I've struggled with coming up with drum fill ideas off the top of my head. Oftentimes, it's hard to just work with three toms to create something that sounds interesting and not too 'drum-tastic'. In many cases, simply applying rudiments and moving your hands around the drum set sounds flat-out terrible. In addition, you can end up with awkward motions which result in slamming your sticks together or hitting rims at EXACTLY the wrong moment.
So, where do you come up with ideas?