Due to the fact that a vast majority of the shoes sold are Ready to Wear, and many of them are ordered online, it’s very common that they doesn’t fit perfectly. Ideally, it would have been to change that shoe to another model in another last that fits one’s feet better, but it’s often not done. Fortunately, it’s possible to make a lot of corrections both to make shoes smaller and bigger, which even it might not create a perfect fit it can be a great improvement.
Basically the only correction that can be done on a pair of shoes that are too small is to stretch them (bespoke shoemakers has a couple of other tricks as well, but for RTW this is it). The cobbler treats the shoes with a special fluid that softens the leather, and then insert them in a stretching machine which is like a mechanical last where you can turn on different screws to push out on the shoes where needed. It often takes a few days to stretch the shoes where the cobbler periodically screws the stretching machine and increases the load gradually. Width is where it’s easiest to achieve a good effect, partly also on the height of the ball area. You can’t stretch them lengthwise tough or expel the sides of the toe cap at the front (unless it’s a real leather toe puff, not that common at all within RTW nowadays).
How much the shoes can be stretched depends on what kind of shoes it is and where they should be stretched, but generally it’s said that the shoes can be stretched out about a whole European size (for example, from size 43 to 44) on the width. It should be done in two rounds, about half the size at a time, so that the leather and the seams can handle the pressure. To know for sure if the shoes can be stretched at the places you want, it’s always safest to go to a good cobbler and ask. It’s a relatively cheap procedure.
Shoes that slips in the heel area are not uncommon, and it’s a problem that can be solved reasonably quite easily. The answer is called heel grip. They can be bought at any cobbler, or even at a larger grocery store, and are very cheap. It’s a self-adhesive leather piece that attaches to the inside of the heel. Thoroughly clean the lining before attaching them, and place them so that there’s a few millimeters below the top of the heel. If you want to remove them or replace them, it will be easy to remove them and then wash the cement off with some spirits or similar.
According to the exact same principle as above, it’s possible to put a form of distance inside the tongue if the shoes are too big in this area. It can be used to fix heel slippage as well, and also fix issues with the instep of the shoe being too high and laces closing entirely, for example. The most common ones are tongue pads made of a fluffy foam which is quite bad really, but there are better ones in leather from for example Pedaq. These are very similar to the heel pads above, and should be attached in the same way.
The most common form of shoe size customization is an extra insole. They are available in a wide variety of styles sand materials, flat and orthopedic, and so on. As most people understand the philosophy about using an extra insole to make the shoes smaller, there’s no use to go into this further.
In a second post on the same theme I will go into more proper versions of these corrections of fit which a cobbler can do, it’ll be posted in a few weeks time.