Foot orthoses or supports are built to correct biomechanical issues of the feet and to help the biomechanics of the feet. There are several various kinds of foot orthotics and techniques of making them for podiatrists to use and select from. Some people need and do gain from made to order foot orthotics while others can be helped by the easier and cheaper mass-produced foot supports. Which one is right for each person is determined by exactly what is leading to the problems and what the treating podiatrist suggests is best for that individual. All different foot orthotics have got distinct design features and a good clinician will attempt and match those up to the needs of the individual. If that is not done properly, then there may not be any improvement in the problem.
Foot orthotics aren't without their problems. If they are not the right choice for the individual, chances are they won't work. You are also restricted by what shoes you need to use, in that you have to be able to fit them into the shoe and there might not be enough space. There are also types of footwear, such as the flip flops which they just can't be used in. This can present a problem in hotter climates that make closed in shoes required for foot orthoses uncomfortable. There are alternatives, for example, the Archies which have a foot support built in. The shape of the arch supports in these sandals are like what you will get in an over-the-counter arch support, but most likely not as good as what you will get from a customized foot support. Using these Archies do give you a helpful option to foot orthoses, based on where you can wear them and the character of the biomechanical problem. If you do need foot orthoses there is no harm in trying these kinds of alternatives or raising it with your treating podiatrist to see what they think.