I highly suggest getting some spring fin straps. They make getting fins on and off much easier and are a sinch to install. I've got a pair of Cressi-Sub fins and it took me about 5 minutes to change the straps. Keep in mind my fins are a M/L so I ordered a large strap and had to exchange it for a medium one.
The strap also provides for a more comfortable fit. Here's what I got, however there are different models of straps desgined to fit the differnet models of fins out there.
http://www.scuba.com/scuba-gear-113/...trap-Pair.html
Or you can go to the fin section on Scubatoys and find a pretty good selection.