One thing I've really changed my thinking on in the past few years is my attitude towards work situations demanding late nights. I wouldn't smoke a cigarette for work, so why was I making excuses for late nights?

I've got an Ouraring, and track my sleep constantly -- but still have trouble getting a consistent 8.5 hours. But I'm getting better.

What habits did you change?

^ See above for relaxation techniques. It's just a ripoff from yoga.

• Read book before bed, not computer/phone.

• Walk

• Keep room COMPLETELY dark and quiet

• Don't eat heavy a few hours before bed

• Walk, bike, or workout

Are there any other watches/devices which measure deep sleep?

Is there really research that shows people need more than 8 on average, or is that a conclusion you've come to about your individual situation?

I think it also varies for a person. My rule of thumb is, I don't want to make a habit of having my alarm clock be what wakes me up. For me, that means that sometimes I'm up and moving less than 7 hours after my head hits the pillow, and sometimes I'm still sawing logs 9 hours later.

Stress seems to be a factor. Which, ironically enough, means that the more I sleep, the less I need to sleep.