Most ski shops realize that this is a service industry but some just want to crank out numbers. If your buying boots, again fit is primary. Consider your skier type. The boot that works for your friend or instructor may not be the boot for you. A stiffer boot is desired for more advanced and heavier skiers while a softer boot is desired for beginner and lighter skiers.
Stiffness correlates to ankle flex.
Instructors are constantly telling students to step up to a longer ski. Skis are measured in centimeters. Skis should be sharpened and waxed by someone knowledgeable and who knows the expected skiing conditions. Basically, you should be able to twist and kick out of your skis while standing still. Poles should be of the length that if you hold them upside-down just under the basket , with knees slightly bent and elbow pointing down, your forearm is at a slight upward angle to the flat surface your standing on.