I hold doors for men.

Well, I hold doors for everyone behind me, but I include men in this. It seems only polite, although it was not something I was brought up with. I’m sixty-one, after all, and in the era of my childhood, we didn’t hold doors for men. If you were a man, you were on your own.
It’s not a big act of kindness, but it is one that I can exercise daily. A common courtesy, in fact. Something that just makes sense, especially if someone has held the previous door open for me.
I don’t know how men feel about this. They seem to appreciate it.