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The wrong fit in knee-high boots can wreck this on-trend look for you -- and they can be an expensive mistake: Boots don't come cheap. Knee-high boots look best when they're form fitting all over, which means you may have to pass up a pair that doesn't conform and continue hunting for the perfect pair of must-have boots.
Although many women are most concerned about the calf portion of knee-high boots, these boots do need to fit your feet correctly if you're going to walk all over town in them. The right boots will fit your foot snugly at the instep, which prevents your foot from slipping when you walk. If you already have boots that flatter your leg but are too loose in the foot, try adding an insole.
The way knee-high boots fit in the calf can be the deal breaker: They need to hug your calf, and they shouldn't have more than 1/4-inch of space at the top, ending at or just below the knee. Boots that have more space than this look messy, unless they're in a slouch style, which is meant to fit you loosely. Still, a slouch style shouldn't have more than 1 inch of space between your leg and the shoe leather, says designer Chie Mihara in a "Real Simple" article by Yolanda Wikiel.
Try on the boots with the type of socks you're likely to wear with them, to get an idea of the best fit. For knee-high boots, go with knee socks to prevent the leather from chafing your legs. Depending on how you plan to wear them, consider trying them on again with tights or leggings, or over your pants. The boots should feel comfortable, neither too loose nor too tight on all areas of the foot and leg, however you choose to wear them.
If you want to rock this look with pants and jeans, adjustable boots will keep the leather close to your skin for a good fit no matter what. Boots that lace or have adjustable buckles put you in control of the calf tightness. Short women can add inches with tall boots that have a heel or a wedge.