Find your fabric. You can even be creative and find an old blanket that you no longer use. Place your wipe case on the fabric and measure to see how much you need to cut. You don't need so much and you don't need the fabric to touch the lips of the case because a ribbon will be glued over the fabric. I pulled the fabric to the lip and wasn't as satisfied with the result.
Once you cut your fabric, start hot gluing it to your case around the opening. Do your corners last. (hot glue a little bit at a time. DO NOT put hot glue all down one side, then try to lay your fabric down. Chances are the glue will dry before you get to finish laying your fabric down.)
Hot glue both sides. Like I said, I had my fabric touching the lips completely. You do not need to do this because ribbon will cover it.
Add some decoration to the case if you want. I added a purple flower. I glued all the petals down, one by one, because you don't want it being ripped off in your diaper bag or purse.
Add your ribbon. It can be any ribbon you like. Just make sure it isn't too thick. Glue all the way around, bit by bit. You'll need ribbon on both sides of the case. It'll look like double ribbon when you're finished. (MAKE SURE YOU DON'T SUPER GLUE THE LIDS CLOSED. After you glue your fabric, open the case the make sure it isn't sticking. Same goes after gluing your ribbon.