1. Excercise. The more variety, the better. Excercise supports nuerogenisis. 2. Proper diet. Can't believe how much smarter I became in my 40's when I actually started eating vegetables, seeds, nuts, leafy greens, fish, etc. 3. Sleep 4. Hydration 5. Socialize

Lots of research for all of the above, but experiance is the best teacher.