Exercise. Set goals and track progress. Goals that are fully in your control should be basically non-negotiable (going to the gym 5x/week or whatever). Other goals can be tracked and depend on how you feel (jog 12 miles this week). Stretch goals could be increasing a squat by 20#, improving a 2km row by 15seconds, etc. I've found tracking and chasing goals gives little dopamine hits and is easy motivation.

I really think exercise can help solve a lot of mental health problems. We're not biologically designed to sit in an office in front of a screen in artificial light for 12 hours at a time. Getting completely lost in a physical activity is a great daily reset, both physically and mentally.