I write music with various instruments. I usually get stuck on a few chord progressions if I stay on one instrument too long. so I end up rotating from guitar to keyboard, to drums, to even some days the trumpet. I think looking at improvising and writing from different instruments allows you to explore their limitations and strengths, causing me to write in different styles without even thinking about it.

I write a lot on the computer using fruit loops and other software, it's hard for me to get a "Real" sound out of a computer if i'm not playing the instrument myself.