You also need an ace type elastic bandage. When erect, wrap bandage once around cock just below the coronal ridge. It needs to be firm, but not too tight. Place toothbrush head (back, smooth side - NOT the bristles!) against the most sensitive spot - right at the tip where the coronal ridge comes together. Wrap one more time, tightly enough to hold the toothbrush firmly in place against Mr. Pleasure spot. Lie back, turn on, and enjoy.
I find that the sensation is wonderful, but normally not quite enough all by itself to orgasm. Not to worry: Unwind some more bandage, and after leaving a foot or more slack, tie an overhand knot in it. Place over cock and toothbrush, about mid cock, and pull rather tight. Pull the ends apart - one with each hand - to tighten and transfer pressure to cock. It will be subtle, due to the stretch of the bandage. Generate whatever motions seem to work best, and best meet the mood. The more you have to "strain" to get there, the better. One last tip: I find that I can't completely remain still, but rather tend to do some serious humping into the air when fully excited. This causes the "heavy-handled toothbrush" to slip out of place, due to its butt not resting exactly on the bed - it is either too long, or too short. A solution is to place something across the top of your thighs to rest it on - this works great, and results in things staying exactly in place
as desired.