For myself, I went to a free badminton session at a local sports centre (I haven't played badminton for about 30 years!). I met and had a nice conversation with someone I've never met before.
For someone I know, I did some shopping for my mother after playing badminton.
And for someone I don't know, I held open the door of the mini market where I went shopping.
I would rate my day 4/5.