Nobody likes the awful breaking in period of new shoes, but it's advisable to buy shoes that are a bit snug at first in order to avoid them becoming too loose over time. There is an old-fashioned remedy for this issue that will allow you to stretch out your shoes just enough to be nice and comfy, no pain required.
Pour approximately 3/4 cup dry beans in a small resealable plastic bag. Place the bag inside a second bag for added protection. Repeat the process to create a second bag of beans.
Add a few teaspoons of water to each bag, and seal all the bags. The water will cause the beans to swell. This swelling is what will gradually and gently stretch your shoes for you.
Insert the bags into your new pair of shoes. You may need to toy with them a bit to get the bag of beans wedged in where you need the shoe stretched. Take some beans out or add more beans, as needed.
Check the shoes often to see if they fit. If the beans aren't swelling up enough after about an hour, add a bit more water.