Even with a list, packing for a camping trip can involve a bewildering number of items. Instead of tracking down every last thing each time you camp, pack your gear into modular "kits" that hold all the gear in a certain category. It's much easier to pack your first aid box and check off "First Aid Box" on your camping list, than it is to find bandages, antiseptic, aspirin, allergy medication and all the other small items you'd need. You can have a box that holds all your cooking gear, one for the tent and related equipment, and another that stores blankets and sleeping bags.
Pack your kits into sealable plastic containers -- you can find large plastic bins at home improvement stores, and smaller sizes at department stores. Plastic containers let you store your gear in the garage or basement over the winter without having to worry about them getting damp. Make sure they seal tightly, or critters might get into them (especially if they'll be holding any food items or things that smell like food, while camping). Obviously you only want to pack non-perishable items in your kits between trips.
Modular camping kits can make packing a snap. The key is to keep them well-stocked. Don't raid a kit for a flashlight without replacing it, and make sure medical supplies haven't expired or run out.