Keep fragile items safe and organized in dry boxes. Besides cameras, dry boxes also work well for guidebooks or small supplies that might disappear to the bottom of a dry bag. Buy ones with the rubber seals in good condition, and before you leave on your trip double-check to make sure the seals are good by loosely wadding paper towels inside and submerging the box in your tub. If the paper towels get wet, you've got a leak. Sometimes a little vegetable oil on the seal will help.
Dry boxes are a great solution for packing out garbage and human waste too.
Try to get dry bags in a variety of sizes and colors, including clear. This will go a long way towards improving organization and reducing the frustration of hunting through several bags each time you want something. Try using two or three larger dry bags for camping gear and clothing you won't need during the day. Then, use smaller bags for quick access to lunch, camera, first aid supplies, and other day gear. Keep waterproof day items handy.