This technique is not for the impatient, and can take a while to learn the timing. Basically, you want to masturbate until you're just about to come, and then you have to force yourself to stop at the very last moment. If you time it right, you will be able to feel it as some semen rises through the shaft of your penis and will dribble out. Wait for a minute to calm down (if you touch yourself right away you'll come instantly, but it won't be very spectacular). If you wait for twenty or thirty seconds (personal timing may vary) and then start again, you can keep repeating the process, essentually tricking yourself into ejaculating multiple times.

A few things to note about this one. First, be prepared for this to take a little practice. It's pretty easy to stop just a half a second too early (and get nothing) or go a half a second too long (and accidentally come). Also, when you decide to come for real, abandon this technique and just go to town for a great orgasm. If you stop, dribble, and then start again, you don't get the same build-up and release.

Finally, this is a neat technique if you don't have any lube handy but wish you did. Once you've gone through the process once, you can gently squeeze your penis and slide your hand from the base of the shaft to the tip to milk out enough semen to coat your hand and use as lube.