Note: I am going to be expanding this article greatly in the near future. Please check back.
I know you're probably thinking to yourself, "But isn't any blowjob a great blowjob as far as a guy is concerned?". Well, not necessarily. Any blowjob is a good blowjob as far as a guy is concerned, not great. Satisfying a guy is not the same thinking as absolutely wowing him. There are also some things you can do to ruin a blowjob too, believe it or not.
Here are some general tips on how to enhance your blowjobs.
Remember that each guy is different, so you'll need to experiment to find out what he likes best.
Start off slowly. Even if a guy is raring to go, take at least a minute to tease him. Stroke your fingernails up and down his inner thighs and around his balls while licking the top of his penis. You can also lick gently up and down the penis on the underside (the side that is not against his stomach while he's erect). Pay careful attention to the area underneath where the shaft joins the head. In most guys, it's very sensitive.
Another way to tease is to suck on his balls. In the sack of his testicles, you can feel the individual balls. Very gently take one in your mouth and again very gently, suck on it. You can also kiss and lick it at the same time.
Take his penis in your mouth, making sure (and this is very important) that you cover your teeth with your lips. At the same time, firmly grasp the base of his penis with a circle of your thumb and forefinger. Move his penis in and out of your mouth, at the same time swirling your tongue around the head or licking up and down the shaft. It takes a little practice, but you'll get the hang of it.
One alternative to this move is to literally "suck cock". Create suction with your mouth as you're moving his penis up and down inside. Vary the amount of suction to see what he likes.
Now, what should your hand be doing at this point? If you want to prolong the blowjob, then just leave your hand at the base of his penis. If you want to make the whole experience more intense, then you should move that circle of your thumb and forefinger up and down the bottom couple of inches of his penis.
When he starts to come do not remove your mouth. Keep doing what you're doing (it's working, after all) until he has finished coming. Then lick his penis gently a few times as a nice way to finish.
If he then wants to kiss you with remains of his come in/on your mouth, he's a keeper!