There are several things you can do to prevent blisters when your child first gets a new pair of shoes. First, make sure the shoes fit properly. There should be a thumb's width of space between the end of the shoe and your child's longest toe. Second, have him wear thick socks with the new shoes to help reduce friction. Finally, go slowly at first and have your child wear the shoes for short periods of time until they have a chance to get used to them.