It all depends on what sound you're going for. Regardless, make sure you drink lots of water and push the air at a constant flow from your diaphram. Open your throat and rattle your vocal box with the air flow rather than by growling with your throat.
The biggest thing is experimentation and air flow. If you're just grabbin the mic and screamin without any direction, you're going to fuck your shit up. Most screamo/hardcore bands' singers will be fuct in 2-3 years.
Phil Anselmo, for example, had a very unique style, but it was throat-based. Listen to Cemetary Gates--he'll never be able to sing like that again because he did too much screaming (i.e. songs like "Fucking Hostile," "Walk," and "This Love").
Death metal vocals, on the the other hand, are not harmful to your vocal chords if you perform them properly, hence why singers like Angela Gossow and Tomas Lindstrom can do hour sets night after night with little vocal chord damage.
Anyways, that's my two cents...
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We are the resistance, our last line of defense. We are bred to fight for our promised land. Rebels at heart, they will hunt us till the ends of the earth. The chase is on--forever going on and on.
Of all the things to care about, why would I give a fuck about a TV show? That's right--I wouldn't and don't.