I wear either NB Hook & Loop Walkers, or Dr Scholl's Velcro walkers (with gel insoles and cushion insoles on top of the gels), when out of the house, all the time.
Different colors and slightly different looks, works for most occasions, other than very formal.
In the house, I immediately change to very soft moccasin type, BR slippers with a rubber sole.

Flip-Flops cause the toes to grip, and the foot to arch- in a manner it shouldn't, every time you take a step.
This puts an undue amount of strain on the muscles and bones of the feet and most podiatrists will say to shy away from them at all costs. (my uncle was a surgical podiatrist at NIH, & private practice)

A good sandal that has an adjustable ankle strap, an adjustable heel strap, and a strap that is adjustable over the toe area, just behind the toes, is preferable.
I need a very soft cushioning insole and padded straps, because of my sensitivity to pressure.
I've many pairs of sandals, but cannot wear any of them for more than an hour or so. I've never found a pair that is soft enough or comfortable enough.
Walking in them for any length of time is painful, to say the least.