I've noticed that the big mappers online draw freehand (and they do an awesome job with it - +matt jackson , +Dyson Logos and the rest).
Me, I can't draw for shit. Heck, I can't even draw a straight line, as my Saturday Night group can attest to.
I've dabbled with many of the computer mapping programs - Dunjieni (SP?), Campaign Cartographer, Hexographer and the like - I still suck ;)
How do you do your maps (with that voodoo that you do)? Freehand, pen to paper, drawing program, mapping program, find already completed maps and make your adventure conform?