Fogging is a winter recreationist's number one problem, other than staying upright on fast-moving boards. The following are sugggested tips for dealing with fog prevention (that's the kind in a goggle, not around the Golden Gate Bridge).

• Do not overdress. Be warm, but not too warm. Skiing generates heat and if beads of sweat are forming on your forehead, your goggles will be fogging. Peal off a few layers until you are comfortable.
• Snow. If it is snowing and your goggles begin to fog, check to see if the snow has clogged the vents. If the top vent is covered, the heat cannot escape whenever you stop skiing and your goggles will fog. Remove the snow.
• Neck gaiters will direct warm air directly up and into your goggles through the bottom vent, especially if you pull the neck gaiter over your nose. Don't ski with neck gaiters.
• If your goggles do fog, never wipe them clean. To do so reduces its effectiveness. Anti-fog treated lenses will heal themselves given time.
• Never clean your goggles with glass cleaner since that removes the anti-fog coating and only use commercial anti-fog sprays or liquids on your goggles when the factory anti-fog coating has worn off or been removed.
• For glasses wearers, try putting on the goggles before leaving the lodge since this will prevent the glasses from getting cold.
• If you take a tumble (and who doesn't), shake the snow from your goggles, but do not wipe them. Blot the water droplets dry with a soft cloth. Ski them dry or if near the lift, remove them and place them foam side down on your thigh so the moisture-laden air can dissipate and the no-fog coating absorb the remaining moisture.