I painted a pair of black chucks with Mary Poppoins motives - and I love them <3
Sorry, I forgot to take step by step pictures, but I wrote a small tutorial though. As always, I hope it's understandable :D
Draw the outline of the picture on your shoes, using tailors chalk.
I have a chalk pen that's really handy for smaller pictures.
If your shoes are a ligher color you can also use a soft pencil for drawing.
Paint the picture using your fabric paint and a small brush. It's hard to paint thin lines and the outlines will probably look a bit blurry, but if you paint over it a few times and use a small brush it should look fine in the end.
Light color on dark shoes will probably need 2-3 layers of color.
Use the blow dryer on highest setting to dry and fuse the paint.
Usually you need to iron fabric paint to fuse it, but I found out that the blow dryer works as well.
I blow-dryed my pictures for about 5 minutes, taking small breaks because I was afraid that the blow dryer would get too hot.
Use a moist brush to remove any remaining chalk from the shoe, by wiping over the picture you can also test if the paint is properly fused.