I work as a server at a high-end restaurant on 5-hour shifts, which normally wouldn’t be awful, but we’re forced to wear hideously uncomfortable heeled dress shoes and it’s pretty much non-stop speed walking and standing all night.
You are aware of your foot positioning, but what about the rest of your body?
Are you maintaining an organized position?
Torque and Trunk Stability Part 1: How to Stand
Are you doing anything for your feet, ankles, calves or low back?
Some may be building up a tolerance to the amount of time you are on your feet.
Maintaining an organized position throughout your body will help.
Abs on 20% all the time.
Are you doing anything to flush those areas?