Shoe stretchers are ideal for those shoes you can't resist buying in a sale or at a vintage store, despite the fact they don't fit. If you don't want to throw away a perfectly lovely pair of shoes, stretching the fabric on the instep is a simple solution to your problem. While it is possible to purchase a specialty instep stretcher, you can save time and money by making your own with some basic household items and a little creative flair.
Apply rubbing alcohol liberally to the instep of your shoes with an old cloth. This will make the fabric more malleable.
Fill two small snap-lock plastic bags with water. These bags will act as your instep stretchers.
Slide one of the plastic bags inside the left shoe and place it on the instep. It should fit snugly between the top and the bottom of the shoe. Add some more water to the bag, if necessary. Secure the bag to the instep of the shoe with masking tape.
Repeat Step 3 to secure the instep stretcher in the right shoe.
Place your shoes in the freezer and leave them overnight.
Remove your shoes from the freezer and take the instep stretchers out of the shoes. The water has frozen and expanded, stretching your shoes at the same time.
Leave your shoes to thaw for 2 hours and then try them on.
Repeat Steps 1-7 if the insteps on your shoes require further stretching.