Exercise and sauna are truly essential for me and I happen to live in Finland so the latter is very accessible.

I notice how my mood goes down quickly (specially approaching winter) if I don't exercise even if other parts of my life are ok. It doesn't matter that I have some nice goals set, good books to read, side projects, nice games... I just feel very apathetic if I don't do it.

Oh yeah and no alcohol and definitely no coffee.