My recipe is much rthe same as Redhead56's. A lot of intellectual activity, being active in organisations that I belong to. My main interest is Archaeology, I am on the committee of our local society, I am also running a project for the local village society - and I read a lot.
I must confess tthat games of any kind, paper, computer or board, hold no attractions for me whatsoever. I would rather read a book and I am never without my KIndle.
I also agree about exercise. I have ADHD, so I am bouncing around all the time, around the house, walking and gardening. DH tells m that even when I sit down, I fidget and jiggle all the time.