Try brushing your teeth with your non-dominant hand. It's remarkably difficult to do. When I first tried, a few months ago I flat out couldn't do it and I'm reasonably ambidextrous with a lot of things. So, I observed what I did with my dominant hand and then tried to mimic it with the other. There was some improvement, but it was still awkward.
Now, I start out brushing my teeth with my non-dominant, then switch to dominant. I'm still not as fluid, but I can get the job done. I've also switched with how I wash the dishes, style my hair, and a whole bunch of other stuff. It's interesting trying to get the brain rewired.