Be aware that this technique works best on leather/suede shoes. It also usually works on fake leather. However, false leather tends to shrink back to its original size rather quickly, so you’ll have to repeat this a couple of times for the full effect.
If you simply cannot fit your feet into the shoes, then remove a layer of socks and try again.
Leave your sock-clad feet in the heels until the leather cools. This way, the leather will cool around your slightly-larger-than-usual feet, and it will settle into a stretched position. Be careful with the heat. Don’t let the leather grow dangerously hot. If the heat begins to scorch your skin, then take the heels off and try again later.
If you want to break in the shoes a bit more: try bending them back and forth to loosen the leather. Then, blast with heat again for 2-3 minutes to wear in the material. [4] X Research source