My husband’s birthday I always wish him a happy birthday. I sometimes buy a card, or multiple cards. Sometimes I make a card. Sometimes I cut out happy birthdays from paper and leave them in various places in the house like the fridge, near the coffee machine, in the flatware drawer, all over.
I send a card with a check to my niece and nephew every year on their birthdays. I also text them on the day.
I call my parents and sister on their birthdays. Sometimes I send a card sometimes I don’t. When my maternal aunt and grandma were alive I always called them.
I call my MIL, FIL, and text or call my SIL and BILs.
I usually remember 5 of my friends and call or text. There are some others I wish I did a better job of remembering. I probably should put them in my calendar.
Facebook reminds me of the birthdays of lots of people. Sometimes I notice, sometimes I don’t, and I’ll post a happy birthday on FB, but I don’t think your are talking about FB birthdays for this Q.
I don’t want to start any sort of gift exchange for birthdays. I even tell people don’t buy me a gift if I get the feeling they want too.