What’s a hobby you suggest everyone should take up to improve their mental health?

Wax Sealing. You heat up colorful wax in a spoon over a tea light, pour it on a marble slab and then stamp cool designs into it. It is fun to experiment with different mixes, pouring techniques, etc and is very relaxing. Plus, when you are done, you have lots of cool seals. I have a bucket full of them and I like to just sit an go through them.

There is a youtube channel called 'melts' that makes really nice wax sealing videos with no talking.