My work colleague has hip displacia, and is under OT and physio. She was advised to completly avoid the soft, hotter/Ecco style shoes.
They recommended harder soled shoes, with a closure/fastening rather than slip ons and a slight heel, not completly flat. Ballet pumps are the absolute worst style from their orthopaedic point of view.
Pregnancy has left me with no arches and very flat feet, and planter facilitis so I struggle to find comfy shoes, so I have also been following her advice.
I love my clarks hamble brogues, I have 3 pairs now (2bought in the sale) and I also have a couple of pairs of shoes from shoon. I find I struggle with sandles/flip flops that are not completly flat soled, but shoon will usually have something comfy. They are expensive but good quality so will last, plus I think it's false economy to spend on cheaper shoes that don't fit as well.
I don't wear heels very often, but all of mine are from M&S. They do a wider fitting although I usually find their standard fine.
ive also tried the over the counter insoles, but they made all my shoes too shallow.