It took 4 staples to secure each shoe. You could do it with three though if you had a decent stapler, rather than a teensy weensy cracker toy one that I've got. She had fun painting her slippers and then putting stickers on them when they were dry. I made sure that we put stickers over where the staples showed on the inside of the shoes, so they wouldn't scratch her.
I think we're going to do this activity again, because the girls have a lot of dressing up gear and it would be fun to make shoes to go with the outfits.
We painted the shoes with watered down food colouring by the way.