Here's how I did mine, which came out pretty good.
I decided against wrapping the material around the sole. I wanted to get some good use out of my suit and didn't want the sole to wear out. I also didn't think the material over the sole would be very stable, might be slippy. And if walking on a wet surface, I didn't want the material to soak up dirty water.
I used a pair of red 'flossy' slippers of Ebay. Very similar to the kung-fu slipper posted above. The red flossy slippers also have a redish sole, which blends well with the suit. The picture below makes them look more brown than they are.
I've turned one foot inside out. That is how I attached them.
I cut off the very sole of the suit, then stretched the material around the slipper as seen on the shoe on the left. Note the slipper looks the wrong way round, this is so when you reverse it, its the right way round and it hides the 'seam' where the suit and slipper attach.
I used dots of glue to hold them together and sewed them for added strength.
Carefully turn the leg inside out and you end up with something like the foot on the right.
I hope this helps. If you have other questions theres some useful info in my -'My Spiderman(Rami)' topic here on the forums, or you can see more with images in the 'Making of' album on my FB page, link in my signature.