It's such a difficult issue! I'm currently nursing a pair of rub marks on the top of my feet from the silver slide lovelies listed below. I knew based on the stiff metallic leather that they'd do this when my feet started to sweat in them - I usually reserve these for non-walking occasions but was unwise and thought they'd be OK for "a few blocks" which detours turned into more than expected.
I think to a point it's a matter of experimenting with your own lifestyle and feet and brands, but agree it seems like we have enough collective knowledge we should be able to pull together some sort of guide, at least!
For me, I know suede and/or elastic is the best material for uppers to avoid blisters. Very soft leather is second. (see finds - a pair of elastic upper slip on oxfords that are on my wish list, as well as a pair of sandals I own)
Patent leather sandals is asking for a disaster. Patent pumps, not much better...I can get away with patent if I wear socks and the shoe comes up high enough to not rub on the skin of my foot...but, even then it's a risk because the stiffness can cause cuts at the heel.
I know that in shoes that will make my feet sweat (patent leather, plastic, or very closed-up shoes like leather lace-up oxfords) that I have to wear socks or stockings and/or be prepared to avoid too much walking.
I also know that a chunkier, shorter heel is the only practical one for me these days. Shoes that have required heel grips never become truly comfortable. Foot petals are best for when you have an open toe heel that your foot slips forward in...they do NOT help significantly with ball-of-foot pain from heels that are too high and worn too long to walk or stand in.
For true comfort I need a cork or otherwise formed footbed on a flat shoe (like the sandals and Birks attached). Simply being flat isn't good enough, because I need arch support...I once wore a pair of Sam Edelman gladiator sandals to tour Chicago and ended up pulling a ligament in my foot...on our first day in town. I was a hard lesson to learn!
