Feet and Pointe Shoes are complex things and no two feet are ever the same. Whilst I would never really recommend self-fitting, unless you are very experienced and confident, here are some indicators to help you check the fit of your shoes.
The foot in the fully pointed position curves and shortens, the strength of the foot, experience and duration of Pointe Work, will help determine what shank strength and shank length is best for the dancer. Usually, a lighter more flexible shoe is desirable for a young petite beginner.
Prepare yourself. Check wear and tear on any toe pads or toe protectors that are used. Padding of any kind will alter the width and fit of the length of the shoe by sometimes half to a full shoe size, so it may change the space within the toe box for the natural foot size and subsequently affect the fit.
Did you know that you can have minimal padding, without the use of big bulky and heavy gel or silicone toe pads or pouches, yet still achieve more pain relief and comfort from other types of toe protection? Ask about the best solutions for you and your feet!
Take notice of any continuing problems eg. Blisters in same area, problems with little toe or second toe being longer than the big toe, big toe with excessive pressure, damage to nails, bunions etc. These can all be indicators and should not be ignored. Often there are remedies to assist with these issues. See the Pointe Clinic information page if you need help
Whilst standing, look at the general shape, width, and length of the feet and note the shape and length of the toes.
A pointe shoe should fit like a second skin, being the same width and length as the foot. If the dancer cannot feel the end of the toe box when in a demi-plie, a shorter shoe may be needed so that toes touch the internal edge of the platform.
Check the width of the shoe at the ball of the foot. The dancer should feel the sides and support across the widest part of the foot with all five toes flat in the shoe.
If the dancer has one foot larger than the other, ensure shoes fit to accommodate the larger foot. If necessary buy two pairs of different sizes to make up two different pairs of Pointe Shoes. Remember Pointe Shoes do not have a Left and Right foot until you wear them and break them in.
Check of the width again by applying weight to the platform (en pointe), while keeping the other foot flat on the floor. If the pointed foot slides downward into the toe box the shoe may be too wide, but also there may be some other common problems where the big toe is not yet strong enough to remain straight en-pointe and "knuckles" inside the toe box. Look at the outer sole and check that it lies flat to the sole of the foot. If the outer sole is twisting, there are a number of reasons this could be happening - too narrow, wrong toe box shape and mechanical causes, such as foot - ankle alignment.
Check the length at the same time, look at the back of the shoe while applying weight into the toe box.There should be a small pinch of fabric at the back of the heel. In the pointed position the foot is contracted and therefore shorter in length.The pinch of fabric should disappear when standing flat or in demi plie.
A properly fitted pointe shoe should not allow for growing room. An exact SNUG fit is required to support the metatarsals and to enable the dancer to stand en pointe. Conversely, a pointe shoe that does not have a slight pinch at the top of the heel, when standing en pointe, is too small for the foot to expand properly on the flat and equally as damaging and dangerous as a pointe shoe with too much space and growing room.
I have known many variations in the size and fit during a fitting when the feet may be cool and then the young dancer finds that their feet feel different in the shoes after they have been active all day or dancing and completed a Ballet class session, so that their feet are very hot.
If you are uncertain about your shoes when you get them home and try them again, DO NOT WEAR THEM OR SEW ANY RIBBONS OR DARN THE TOE PLATFORM !
Get your teacher to check them and if needs be return with them to enable you to have another re-fit.