One thing that has really helped me has been practicing mindfulness. If you google, there are all sorts of great articles that cover it.

It's good that you recognize the risk inherent in mania- although there is some freedom in the experiences, your mind doesn't feel constrained by anything- there is a lot of risk. When I was manic prior to my diagnosis, I almost died.

For me- the experience of happiness has been more subtle. Hearing a child's laugh, seeing my daughter figure out how to read a word, getting hugs. If you can find a way to experience joy in everyday experiences- that makes a world of difference.