Sing at least one foot from the mic so you don't overload it. Watch the levels on your compressor and mixer very closely so you don't overload either one of them. It's very easy to distort any and all of these with screaming vocals, since they're just so damned loud. On the mixer, EQ out some of the low end and then compress the living hell out of the vocals. I'd recommend using a 4:1 or more ratio and a really low threshold set so that you get about 9db of gain reduction (you can set it for less if your screaming is consistent, but most people tend to drop in volume towards the end of a phrase because they start running out of breath). Of course, if you have software compression, I'd recommend that during recording you just compress enough so that your levels don't clip, and then do the rest during mixdown. Also at mixdown, try cutting some more lows at around 200-300Hz, and boosting the highs above 8kHz.
Finally, if you have enough tracks and are a good enough singer, try doubling the vocals and applying different EQ, verb, and compression settings to each. Beware, though, the performances have to be very, VERY similar, or else it'll sound echoey and mushy. But if you get it right, it'll sound thick and powerful (check out anything by the Foo Fighters for an example of this sound).
If you'd like to hear an example of what some of these techniques sound like, listen to "Dead Alibis" and "Say a Prayer" at
http://www.mp3.com/37point5/.
Ryan
