I'm keys+ vocals not using a headset so I have some leeway in head position. I've had a small amount of vocal training which helped my voice control quite a lot. I use a compressor / limiter to help control things a little more. I still find it necessary to back off at times.

Certainly the vocal technique demonstrated in all the videos is really good nevertheless I'd expect all the big names will have a top notch sound man who knows the arrangement riding the sliders.

Personally with one pair of hands and no sound man I find the compressor invaluable.

Net's not forget that these people look effortless at the top end because the song will be carefully arranged to suit their range and not overstretch the voices, you can't do this stuff night after night on tour or in a residency if you push your voice too far too often. The fact that these guys are relaxed singing in keys that us mortals can only dream of is one reason they are where they are.

I've always taken tine to work the best key for any song that I sing and this is the first bit of advice I give to anyone starting out in this business. It's very nice to be able to do stuff in copy but it's not worth ruining your voice in the process.

As a more general point I'm certainly not going to beat myself up because there are people out there who are better than me, it's a pretty big list!