Arguably, your most important piece of ski equipment is your boots. If you're not wearing a quality pair of ski boots that are properly fitted, your skiing and feet will suffer. Proper fitting ski boots transfer movement from your hips, legs, knees, and feet directly to your skis.
The Proper Fit
The general approach to getting a good fitting boot is the same whether you're a man, woman, or teen. It all begins by working with a trained boot fitter - one who's certified by all of the major boot manufacturers in how to properly fit their ski boots and is familiar with the nuances between their offerings. The best time to get fitted is late in the day when your feet are at their largest. Make sure you wear your regular ski socks. The best types are made of a material called Smartwool, a blend of wool and synthetic fibers that wick moisture away from your feet. The worst mistake you can make when getting fitted for ski boots is to wear a thick pair (or two) of socks.
The next step is determining the correct size boot shell. The boot shell is the hard plastic outer layer that provides foot support and transfers movements to your skis. It is the most critical part of getting a good fit. Pull the liner out of the boot shell. Slide your foot into the boot shell and scoot your foot forward until you can feel the end of your toes against the front of the boot liner. Slide your hand down the back of the liner. You should be able to insert one to one and a half fingers between the back of your heel and the back of the boot shell if you're in the correct size boot shell.
Once you've identified the proper boot shell size, push the boot liner back into the boot liner and slide your feet into the boots. Don't be concerned if the boots fit perfectly at this point - there are plenty of adjustments you can make to get the perfect fit. Fasten the buckles across the top of your insteps and flex forward with your ankles. Alternatively, you can bang the back of the boot heels against the floor.
The important thing is to get your heels firmly seated into the heel cups. Fasten the rest of the buckles firmly, but not to the point where they restrict the blood flow in your feet. Properly fitted boots should feel like a firm handshake. You should be able to wiggle your toes and your heels should stay firmly in the heel cups.
Take 15 or 20 minutes to walk around inside the store and get a general feel for how well the boots feel. If you're looking at two or three other models, repeat the same process for each of them. The only way you'll really know how well boots fit is to try them on and walk in them - actually, ski in them if the shop has a demo policy.
No boot fitting process is complete until you've been fitted for custom footbeds, often called orthotics or skithotics. Footbeds are essential to the way the boot transfers movement from your legs to the skis. Because they do take up room inside your ski boots, the best time to get fitted is at the same time you're getting fitted for your new boots.
Fitting Kids' Boots
When it comes to fitting ski boots for kids, the most important feature of the boot should be comfort. Children between the ages of 3 and 9 are more concerned with being warm and comfortable than how well their boots perform. Since they'll probably be getting new ski boots next year anyway, aim for a good fitting boot but don't worry about the subtle nuances you care about as an adult.
The shape and size of many women's ankles and calves can make boot fitting a challenge. If you have trouble getting fitted in traditional unisex ski boots, be sure to try some of the women's boots on the market. With wider cuffs and narrower heel cups, they're designed to accommodate the unique shape of a woman's foot.