Ill start with the 3 that I think we should all prioritise everyday!
Meditation- scientifically proven and only requires 10 minutes! Really time efficient way to boost performance and positive emotion.
Exercise- short bursts of intense exercise raise levels of BDNF in the brain keeping us mentally sharp and happy as Larry- winner.
Journaling- I love to write first thing in the morning. Practicing gratitude daily by writing down what your thankful for has huge benefits, I also like to build on my self knowledge by journaling about whatever emotions I may be feeling that day (huge parts of our emotional world can remain in our unconscious and in the dark if we don't shine a light on them).
Let me hear what you are doing to keep your brain in top form :)