I googled shoe application patterns and got a few sites with free patterns so you might want to do a little 'searching' to see the comparison.
I definitely don't have the talent to paint the shoes. However, if it were within my budget I might purchase pre-painted squares or 'prints'. Seems like someone mentioned on the board the other day that she has her paintings professionally printed on fabric. This might be something to look into. who knows, maybe you'll wind up designing a fabric line!