Face to Face

One gets his legs over the other, one either side of his waist. Move close together until your joysticks touch so that one of you may hold both at once. It's rather fun to put both penises together and masturbate them, feels surprisingly good because the precum from his penis and yours are going together to make more lube. And you consistently have the entire shaft of your penis being rubbed on one side by another.

Now masturbate each other face to face. Sit up and hug each other or lay back and go for it. This is more intense because it more closely simulates intercourse-style contact. Kissing makes this even better.

This position is good for practicing multiple orgasms together. Bring each other close to ejaculation and stop. Relax a moment. Go for it again. Do this about six times.

Foreskin Tease

This is a variation of the game above. Hold each other's foreskin back and stimulate each other in other ways (stoking your bodies, kissing, whatever) for as long as possible. Then, when you can't stand it anymore, begin to masturbate each other very fast until you reach an orgasm. Definitely recommended.

Helping Hand

One person masturbates the other, who just lies back and enjoys it. Slowly bring your friend close to ejaculation and stop. Then you switch over and go for it again.

A downside is if you're doing this to ejaculate, one person must cum first and therefore may not be as interested in helping the second person to orgasm. Tantra practice will help you overcome this little problem.