I tend to read...a lot. I love the library, the atmosphere, the sounds, the people the smells...bookstores, just being there is a wonderment for me and relaxing. I confess there has been a time that my personal "library" at home gets too big and I either sell them or most times donate them, but all in all reading, writing are my guilty pleasures and "go to" places.
I agree with the posts above that just changing activities up or making them "new" in some ways are also helpful. My own example is that reading more fiction vs. non fiction has new possibilities for me. I am hoping to eventually "join" a book club as a possibility.

I wish you luck this year MJ on your boxing lessons. You are brave, I don't know if I could take a punch!
Jade