For me, they have to have wide boxy toes, no high heels--wedge type or flat heels only. They have to be high on top, and adjustable, such as laces, as I have long, wide feet, that are high on top in front of the ankle. Also, no inside back seam behind the heel. Those back seams always chafe me raw, so I avoid them. The foot gear also has to be cushiony inside, as I have bad feet, and they should have rubbery, or gummy, athletic shoe type soles as I have an unsteady gait. Between the cushioning and the athletic type soles, that helps me maintain my balance better, with my unsteady gait. I have always had feet that turn out a little, and now have bad knees, so I need what help I can get in that department.
Before buying foot gear, I take the time to examine the ones on display carefully to eliminate from consideration, those that definitely won't do. That way there are fewer for me to have to try on. By doing that, and by knowing what I want, I reduce the stress of shopping for foot gear.
Many years ago I must have driven a sales girl at an eye glass store crazy, while I tried on many, many different pairs of glasses, to find a pair that fit. I am hard to fit with glasses. I am also particular about color. However, I did make up for it by finding--and buying not one, but TWO pair of glasses. I had them turn one pair into prescription sunglasses, so that added to their profit. The girl was very nice, even though I am sure she was somewhat frazzled by the time I was done. I did try to let her know how pleased I was at finding two pair of glasses that fit, though, and how much I appreciated her help.
Just take your time to check out the display foot gear, and then buy what you like. Don't be a slave to fashion. And remember, we on the spectrum are all:
A Different Drummer
If a man does not keep pace with his companions,
Perhaps it is because he hears a different drummer.
Let him step to the music which he hears,
However measured, or far away.
--Henry David Thoreau