I was wondering how I could produce the harmonics that you can heard in songs of band like Despised Icon, Ion Dissonnance, Job for a Cowboy and Beneath the Massacre.

I already know and able to produce pinch harmonic like Zakk Wylde, Laiho, etc. but I can't seem to hit the right spot or technique to make those really high squeals.

It sounds really chaotic and I like that so... please anybody can help me to achieve te sound or redirect me to video or something.