I spoke a lot about this exact issue during my recent dietician sessions. I wouldn’t say brushing teeth is a good reward 😂 I have certainly suggested that on here before, but more for if you’re staving off hunger.
To stop myself eating through boredom/as a reward/stress reliever, I do one of the following:
have a tea/sparkling water (I love it),
deep breaths, star jumps, a moment of mindfulness eg visualising future me,
paint my nails,
do some painting,
clear out a cupboard,
do a workout.
Mainly things that absorb me so I’m not thinking about food.
The problem is, most of these things are much more time consuming than eating and you can’t multitask while doing them. That is the point, but also very impractical if you have other stuff to get on with, eg entertain kids, work.
Being aware that you’re eating for reasons other than hunger is a big thing, so well done on that. Work on your mindfulness - guided meditations as you’re falling asleep can be helpful. I also was going to the cupboard for every transition - come into the house - go to the kitchen; finish some cleaning - go to the kitchen; about to start up an activity again after having lunch - go to the kitchen (yes really).
Hope some of that helps!