1) Make sure your boots fit properly. Your ski boots should fit comfortably, without feeling too loose or too tight, in order to allow proper circulation. When blood is flowing, your feet stay warm. But, boots that are too loose can become cold quickly.
2) Don't overtighten your boots. Your boot needs to be sturdy enough to withstand the forward-press of your shins throughout your turns, but that support needs to come primarily from the boot fit, not from tight buckles. Having boots that are too snug can be just as much of a problem as having boots that are loose, as circulation is cut off, restricting blood flow and resulting in cold feet.
3) Look for insulated boot liners. Most boots feature liners that are relatively well-insulated. Ski racers' boots, however, are known to be especially cold, as their liners are very thin. When shopping for ski boots, make sure to inquire about the liners.
4) Wear the right socks. This might just be the most important strategy to prevent cold feet. Don't even think about wearing a pair of cotton socks pulled blindly from your dresser drawer. If you want your feet to stay warm and dry, you really need a pair of ski-specific socks. Look for socks that are knee-high, breathable, moisture-wicking, and of thin or medium weight (if they're too heavy, your feet will sweat and get cold quick).
5) Keep your body warm. When your body is cold, the warmth flees from your extremities. You can help reduce this effect by wearing an insulating mid-layer to keep your core warm, such as a fleece or a vest.
6) Consider bootgloves. Some skiers wear bootgloves, such as the Dry Guy Bootglove, over their boots to seal in some extra warmth. While it's not a surefire way to ward off cold feet, it does protect against excess wind chilling your toes.
7) Invest in battery boot heaters. Battery-operated boot heaters can be inserted into ski boots, and are extremely effective. Hotronic is a popular brand, as is Therm-ic. Unless you're crafty, you'll probably have to hit up a ski shop for the installation. While the overall cost varies, expect to pay around $200 - a pretty good investment for surefire warm feet.
8) Try footwarmers. Some skiers swear by disposable, insertable footwarmers, but be sure to use them with caution. They shouldn't be worn against bare skin, because unlike handwarmers, if they start to heat up beyond your comfort level, it's not so easy to remove them. Another concern is that they can cause your feet to sweat excessively, which can actually make your feet even colder. To amend that problem, Heat Factory has introduced heated socks that feature a pocket for the warmer.
10) Wear the right snow pants. Wearing insulated snow pants will keep your legs warm, and thus help prevent blood from fleeing your toes. Also look for snow pants that have gaiters you can pull over the shaft of your boot, further blocking wind gusts or icy chills that reduce warmth.
12) Choose a warm spot to buckle up. If possible, on the most bone-chilling days, you should avoid putting your boots on in the parking lot, or on a bench outside. As it goes with your hands, once your feet get cold, they tend to stay cold.
13) Wear one pair of socks. Dress your body in layers - not your feet. Wearing two pairs of ski socks will reduce the breathability component of the socks, resulting in sweaty (and cold) feet. In addition, double socks tend to get bunched up easily within your boot, which can cause distracting pain and irritation.
14) Cold on the lift? Don't clench your toes. Many skier mistakenly clench their toes when they're cold, but this restricts blood flow, only exacerbating frigid toes. A better option is to swing your feet back and forth - of course, being mindful of your skis - to get warm blood from your upper body back to your feet.
15) Take advantage of your lunch break. On the coldest days, take your ski boots off during lunch to allow warm blood to re-circulate. Once you feel the warmth creeping back into your toes, you can put your boots back on. If your feet tend to get especially sweaty, stash an extra pair of socks in your pocket to change during lunch, so you can ski the rest of the day with warm, dry feet.
Read More: How to Keep Your Hands Warm Skiing