I wasn't as good when I started off but I got better through practice, hard work and experimentation. That's the jist of it.
Now on to the bread and butter of my contribution. I'm not dismissing "vocal fry" here, I'm just giving an alternate technique for aspiring death vocalists (screaming/growling).
What is "death chord" technique? Well it's a different way of doing "unclean" vocals resulting in a different sound. It's an already established technique, but I'm going over it anyway. Death chord screams and growls sound "less human" than Vocal Fried ones, and they may appeal to vocalists who desire to do death vocals. I myself use death chord screams and growls as my primary unclean vocalization style.
Death screams vs VF screams: Death screams are less raspy, hoarse and deep than VF screams. They are "whistle register" breaking usually. If you want a good example of a death screamer than George "Corpsegrinder" Fisher and the screamer for Napalm Death are good examples, Corpsegrinder however uses a more vocal fried approach to his growling technique though.
Death growls vs VF growls: Death growls are generally deeper and again "less human" sounding than VF growls. I can't really name a good death growler since many growlers use gimmicks such as cupping the mic and pouting their lips while clenching their teeth to deepen their growl. You can actually heighten a death growl though without use of vocal fry or falsetto.
"How do you perform with death chord style?"
Death chord style is typically very gutteral, it utilizes your death/false vocal chords rather than true vocal chords, resulting in a voice that sounds absolutely nothing like you, nor does it sound human in any shape or form.
Death Scream: Make a fake "choking" noise, it should be higher pitched. If you speak regular like this you should sound like a high-pitched "demon".
Death Growl: Make a fake "burping/gurgling" noise, it should be lower pitched. If you speak regular like this you should sound like a low-pitched "demon".
Those are just the basics though.
"How do I expand my Death Chord range?"
Experimentation with the basic techniques is key, if you keep experimenting and practicing you should be able to eventually growl at a higher pitch with a just as inhuman sound, and no it won't sound like a scream, it will be more "gurgly" and have less volume just like the low growl rather than "choky" and louder like the high scream.
