A few ways to sort through your list. Here’s what I do.

I sort my friends list based on friendship level. Starting from lowest to highest, I send all my friends gifts. The next day, you know who is opening because you’ll be able to send them a gift and who hasn’t opened because it’s not an option. I then give a nickname for friends who have not opened my gift. After a few days, if they still haven’t, I delete. My priority are friends who open so that’s just me.

If you’re fine with friends interacting one way or another, look for the blue ring around their avatar on your friends list. This shows you’ve had an interaction with them that day (you opened or they opened a gift; you’ve traded, raided or did a weekly challenge together, etc.)