When you first start learning, you're going to be making a lot of dodgy noises. Like little cat growls and trying to speak like Marge Simpson. It's important that you create your scratchy sounds from the nasal region in the back, above your throat, not low in your throat. If you make the sound from low in your throat, you will be teaching yourself to do it wrong and learning a method that will hurt you. Try to feel the difference between the Marge voice and the low-in-the-throat, gargle-like noise. You should be able to create the Marge voice without hurting yourself. Use these two points of reference as you're learning. Remember to keep your scratchy sounds coming from higher up (the nasal region) so you don't damage your voice. If you're doing it wrong, it will hurt like hell. Practice intelligently. You will probably be screaming wrong in the beginning, so save your voice until you figure out how to do it right.
http://www.wikihow.com/Properly-Stress- ... -Screaming
Always always always make sure you have enough air to support your sound.
Keep your throat loose and relaxed, like a when you're yawning. If you squeeze it, it will sound more like a screech.
To aid the dropping of the jaw and raising of the uvula, it is helpful to think that you are politely yawning, or are about to sneeze. Do not drop your jaw as you sing, but rather drop before.
If your voice cracks when you hit the high notes, it is likely that you are singing from your throat, which damages your voice. Push your larynx down your throat. This action is also achieved by trying to yawn politely, sneeze, or in this case, retch.
To prevent any abrupt changes in tone, it helps to think that the two notes are lying just next to each other, rather than far apart.
Avoid tensing up before singing the high note; this leads to the tightening of throat muscles and subsequently the cracking of the voice. Many singers tense up because they are daunted by their apparent inability to hit the high notes, even before singing it! Overcome this by believing in yourself.
http://www.wikihow.com/Hit-the-High-Not ... ical-Style
Practice barking like a dog. Take a deep breath and go from your diaphragm. Force the sound out from the bottom of your belly, really imitating the barking sound. Then extend the barking sound and try it with several words. Breathing like a dog, as stupid as it sounds, can help you open your throat and get a guttural sound to your grunts. Don't do it loudly at the beginning--increase your volume as you get better at it.
http://www.wikihow.com/Do-Harsh-Death-Metal-Vocals
