This is directed toward the girls, but any guys with advice, feel free to chime in:

What's the best way to "comfortize" a pair of pain-inducing shoes? The shoes in question are all flats or low heels/wedges, so height isn't the problem - the stiff backs and sides dig in, and I end up with blisters on the back of my heel and top of my toes. I've tried those cushiony pads that stick onto the back of your shoes, which help a little with the heel part, but not the top or sides.

I do want to wear the shoes I already have, but if there's no satisfactory way to make those comfortable, what brand of shoes (not sneakers) is really comfortable right out of the box? I'd need to be able to walk about two miles in them every day.