How to add a detachable pom pom 1.sewing a button inside the crown of your hat and pulling the elastic band that's attached to the pompoms inside and over the button 2. Position the pom pom on the outside of the hat, opposite the position of the button. use a crochet hook,or other handy curved tool,and insert it through your hat from the inside out, through a hole in your knitting close to the button. Use the hook to grab the elastic loop. 3. Pull the hook with the elastic loop into the inside of the hat, and wrap the elastic loop around the button. You may need to wrap it around the button twice to strongly secure it. 4. with this simple button trick, you can wear a hat with or without a pom, or switch the poms out to fit your mood. A simple hack with big.