Tipping collie's ears

My parents have a 4 month old Collie puppy and her ears started off perfectly tipped but now one of them's starting to prick up and they'd like to make it tip over again. They came to me for advice because my Sheltie's ears are perfectly tipped and they figured I must know what to do, but I had to tell them that I just got lucky and his turned out that way all on their own! I looked around a bit on the internet and found various things, mostly involving either moleskin or various sorts of tape, but I was hoping someone here might have some personal experience with what works best/easiest. Thanks!