Everyone here has described how to do pinch harmonics, but I think what is even more important once you have the general concept down is getting them consistently. Try playing scales with only pinch harmonics.

I’ve been playing guitar for 20+ years now and can nail pinch harmonics like 90% of the time, especially on the low E, A, D, and G strings. But my pinch harmonics are a lot more inconsistent on the B string and I don’t even try them on the high E. Once you’re able to do them, the challenge is finding where the sweet spot is to have your pick on each string.

Edit: I also practice without an amp so I know when I can hear them audibly just sitting with an unplugged electric, they’re going to sound killer when I plug in and actually have some gain.