Some hobbies translate better to writing than others. For instance, my grandmother attempted to teach me to knit at various stages of my life with varying success. When I went off to college, it finally stuck. When I was writing my last novel, I thought it would be useful to have my character be able to knit—at least so far as darning socks is concerned.
Let me tell you something about knitting, it is mind numbing. I usually work on it while I’m doing something else—like watching TV or listening to a book on tape, because otherwise I would lose all interest in the project.
If the actual process is that mind-numbing and dull, imagine reading an entire paragraph where the only thing of note that takes place is that the protagonist darns a pair of socks. It was awful. Don’t do it.
So I suppose a good rule of thumb for hobbies is that if it is boring in real life, it won’t translate well to paper.
Other than writing itself, I don’t really see any of my hobbies cropping up in my stories. Perhaps if I wrote urban fantasy instead of doing world building, I would see more of an inclusion, but somehow sitting in front of a TV playing video games all day doesn’t really fit in to a sword and sorcery style novel… and I’m not about to attempt to pick up swordsmanship… that’s a good way to end up with broken or missing fingers… and then how am I supposed to write?