This reminds me of a bit in one of Bill Burr's standup shows, where he says that if a woman wants to make her boyfriend/husband happy, she should make him a sandwich, hand him a beer, and then leave him to whatever he was doing before you came in.

I think a lot of people forget about the random act of kindness, and how it can go a long way towards making people much happier. It can be as simple as stopping to let someone cross the road, making your partner a sandwich, tidying the house, or even leaving a nice reply to a tweet.