Pound my head on the table until I see stars or drop shadows. My process may be long and slow. Usually I keep designing it until it feels right... sort of trial and error. Most of my process takes place on the screen. It is easier for me to visualize it in real time. Sometimes ketches may help, but the proportion may be off, therefore the solution may not work. If pounding it out like that does not work, I just take a little time off and read, maybe surf a little. And then come back with a fresh head.