1. Gym at least 3 times a week
2. 30 mins meditation before bed (even driving with zero music has a similar effect but is obviously no fun
3. A good nights sleep
4. A night out with good friends
5. Daily regular interactions with people, work colleagues/housemates/whatever
6. Reduced evening 'screen' time, ie, less Facebook zoning out while watching a TV programme you don't care about