Listened to this one (+ its follow-up, “Habits for Happiness at work”) for free through Audible.
There's the usual suspects - getting enough sleep, getting enough exercise. Tim Sharp also recommends creating a vision board for what happiness would look like for you, and then setting SMART goals to work towards achieving them.
One highlight for me was the mention of the “tyranny of when” (which after Googling looks like is a phrase he coined himself). i.e. we shouldn't be falling into the trap of “When X happens I will be happy”. I'm definitely guilty of this one!
Might be worth a listen if you've used up your credits on your Audible account but I wouldn't go out of your way to listen to it otherwise.