According to a guy poll done by Cosmo, here is a list of things that will send him into a downright dizzy:
Drawing circles around his nipples with your tongue so they get hard—then gently pulling at them.
Putting your palm over the tip of his penis and massaging just that area, like it’s a doorknob.
Giving him a hand job while barely using any pressure, so you have a light grip on his penis.
Taking his hand and pressing it against your underwear so he can feel how turned on you are.