every time i try on a pair of flats, they don't seem like they fit right. they either feel like like they're too small and my heel will blister when i wear them, or they feel too big, and my heel will fall out while walking. i wear a size 8 1/2, but when i try on an 8 1/2 they seem to small, a nine too big. am i supposed to get the smaller ones and let them stretch?

Often when a someone states that the grabbing on leaves blisters and the sliding off the heel causes pain, it's because the shoe is not properly fitted in the toe area. Make sure that the area that covers the toes is substantial in coverage because the area behind the toes, toward the ankle, is what holds us in place in our shoes. It is possible that you need a bit more front coverage to get that leverage. I would also search for shoes that are of soft, deertan like leather, that have a flexible sole (like Aerosoles) and feel like a glove when you first place them on your feet. To be honest, breaking in of a shoe is a myth; it feels comfortable from the first or it's not appropriate, no matter what a shoe salesperson tells you.

thanks!