We generally recommend wearing an insole where the arch height of the insole is close to that of your foot. In other words, if you have low-arched feet, we recommend a low arch insole, but if you have medium-arched or high-arched feet, we instead recommend a medium-arch insole or high-arch insole instead.
If your foot arch is between two foot arch heights according to the Wet Test (i.e. your foot could be considered medium-arched or high-arched), the general rule of thumb is that a higher arch will provide more support while a lower arch will provide less support, and you can choose either high-arch or medium-arch insoles depending on your preference in this case.