Most likely, very much the same as when a man sucks your clit and licks it. Man vs women, our parts aren't the same enough to give you a perfect example. You cry sucking your thumb and imagine the tip of your thumb the "head" and how it feels is your clit, again. And remember, the clit is on the end of a stalk (bundle of nerves, etc) so I've followed that down with my fingers and tongue. Drives women wild.
The best? From my wife... why? Because she enjoys making me feel good, she'll play with my dick and balls on her own, even while watching tv. She's the first woman to play with and enjoy my privates.