Julie, if you do a search for “labels” or “labeling”, you’ll find numerous threads like this: I think I figured out How to Label My Crosses
Personally, I use a piece of 3M blue masking tape folded around on itself below the peduncle, identifying the father with a laundry Sharpie. I’ve never lost one, and they are usually easy to see even in thick foliage, or on the ground if the hip aborts.