My brother just bought the car and the guy told us he laid out his design, then trimmed and sanded the foam. Then glue and roll on the vinyl. It looks very nice.
I work in a shop and I never understood why people don't like mini spares. A spare tire is designed to get you to a place to repair your car properly. My thoughts are that if it looks stupid on your car, maybe you'll be more motivated to get the tire fixed more quickly. Hopefully you will never need to use your spare anyway.