There's nothing better for a guy than to have one or both hands around the base of his cock pumping away as you suck on the tip. Start by caressing his inner thighs while your're sucking on the tip. As you go deeper and deeper down the shaft, begin to caress his balls. Be careful here, as some men are very sensitive. Almost all of them will enjoy it in some form or another. Try using one hand to pump the bottom third of his cock as you suck away at the top part. Pretend that you're using your hand to milk every last drop out of him.