The most important part of learning ballet is having comfortable shoes. If your shoes are the least bit uncomfortable or poorly fitting, then you will have trouble dancing and learning moves. Even if they seem comfortable, they might have some aspect that makes it more likely to sustain injury to your feet. If you have feet that are usually hard to fit in shoes (if they are especially wide or tall, for example) then you may have trouble searching for the right ballet shoes. But no matter what, you should be diligent until you find the perfect ones.
You should look at the particular shapes that your feet make. The outline of your toes can range from an almost perfect square to very rounded. Your shoes should fit the shape of your toes very well. Some people have a 2nd toe that is longer than their 1st toe. This needs to be accommodated, otherwise you will be uncomfortable in your shoes. There are different things that can be used to modify shoes for particular toes. These include separators, and fitting kits. You can take a regular shoe, and modify it to fit your feet.
You also need to look at the shape of your foot and see if it has any peculiar properties that you need to keep in mind. Particularly, your arches may cause problems if you don’t accommodate them. If the middle section of your foot is very highly arched, extra material sometimes needs to be added to the shoe to allow for support. This comes into play especially when you are doing pointework on your toes, since a lot of strain is placed on the arch of your foot.
So, make sure that you spend plenty of time finding the perfect shoes for your feet. They should feel like an extension of your body, and not as if they’re just some hunks of material stuck on the end. So when you go to the shoe store, don’t be afraid to try on as many shoes as you need in order to find the best ones. You may have the store employee bustling back and forth carrying boxes of shoes, but that’s alright. When you’ve been ballet dancing for years and your feet are in perfect condition, you will be glad that you went to the trouble.