Great ideas. Here is one that I use when I have stress during the day and also when I am laying in bed trying to relax and go to sleep.

Breathe naturally, silently counting 1 on the inhale and 1 on the exhale, 2 on the inhale and 2 on the exhale, continuing up to 10. then start at 1 again.

The mind cannot focus on negative thoughts and breathing also so the breathing and counting wins out.