Okay so I'm 16 and am interested in learning how to do screaming/growl vocals. Some of my favorite unclean vocalists are Jared Warth from Blessthefall, Winston McCall from Parkway Drive and Trevor Wentworth from Our Last Night. I don't want to be exactly like one of them in they way they scream but I would like to be able to scream like they can. My first problem is no matter how many exercises I do or for how long i practice them, I cannot for the life of me even make a sound resembling a harsh vocal. I've tried dozens of "proper ways" but it's like my body can't produce the sound. I would like to know if this means I just can't do it or if there a physical/mental barrier I need to get past. If I can't do it then I guess I will stick to just singing, if I can then I would like to add the screams/growls to my singing style. And yes I'm aware no matter how much you scream the "right" way you still will eventually do some damage to your voice. I only plan on using screams/growls to kind of add power to some lines of a song, not a whole chorus/verse or even the whole song like all the 'core' bands do.
"One good thing about music, when it hits you, you feel no pain."- Bob Marley
It just takes a lot of practice. Back when I started last year, I had the same problem. If you practice frequently, you'll find a technique that works for you and from there, just keep at it until you get better. The first few times will kind of hurt your throat and once you're past that, it won't bother you as much. What does the trick for me is tightening my diaphragm. Oh, and a little trick that helped me was just grunting or screaming along the vocals to get a decent grasp on it without actually saying the lyrics.

Hope that helped you somewhat
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I've been screaming for 4 or 5 years now and this guy right here really helped https://www.youtube.com/watch?v=ZA_6q-mSwuE

He does a few videos on how to start screaming properly and the do's and don'ts.
Here's his channel too - https://www.youtube.com/user/austin29803/videos

In my experience it's important to warm up first...Just find a few good warmups and it also helps to sing first as a good warmup.

Also there's a DVD called The Zen Of Screaming and there's The Zen Of Screaming 2 (Buy it, download it, stream it whatever) that was helpful.
What the guy calls "power exhale" is just a false cord scream. Look up videos on youtube for it or come to the screaming/growling thread.

The Zen series is rubbish. Her warmup exercises have been known to potentially cause vocal damage in folks who don't have prior training and the majority of her videos are self-advertisement.

OP: I think for Parkway drive vocals and the like you are either going to want to learn rasp technique (vocal compression of the true folds to cause hypervibrations of the soft pallete) or fry. False cord use in the way you are describing may sound a bit too separate from your true voice. Of course, it's music and this is just my opinion so YMMV. \m/ \m/
I watched both of the Zen vids and i have to agree that they are pretty bad. She doesnt really explain how to scream, just has some warmups and how to control when you already know how to scream. Check out some tutorials on false cord and fry screaming. And you have to keep at it, and find your own way. I was stugling for a few months before i actually started doing it kinda properly. Even after almost a year im still far from perfect. But yeah, i feel your frustration, it was the same with me. You just have to push trough and i bet you will get it soon. Perhaps you can even go get some vocal lessons, they tend to help a lot.
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