When you put the fabric strap on your headbands to make it interchangeable, how do you do it? I've been putting my strap on where the seams are, wrapping it around and gluing it with fabric tac. Is this the best way to do it? I want the headband to be pinched in the middle. Or is just sewing the strap on (without being pinched in the middle) the best way to go? My girls won't leave the headbands on so I don't really have a way of testing it out. Help!