Christmas stockings are a tradition in our family and this year I put our initials on them. I was afraid to use an iron because I wasn’t sure if they were made of plastic (they felt furry, but you never know if it will melt or not). Instead I cut the letters out with flock vinyl (because I love the texture!) and used spray glue. It was easy, but not. You have to be very careful, especially with curvy letters like S.
You can find the vinyl I used at Amazon: https://amzn.to/38gfZSv (affiliate link). I love this vinyl and have used it on tea towels and shirts. It is so fun to use!