What do you people do for forearm workouts? I feel like I can't get decent size on mine and the few exercises that I do know don't seem to cut it.

I've been told that gripping bars and such for heavy weight (like deadlifts) will help, but it doesn't get the job done with myself. I also have a pair of those blue rubber things that go on bars to make it harder to grab, but they don't make much of a difference either.