Keep your campsite clean. Never leave stinky dirty dishes or uneaten food lying around out in the open. Wash dishes immediately after use. As for uneaten food, either burn it or store it in your cooler.
Store all of your food in a vehicle at night–preferably the trunk of your car. This includes the cooler. If you are camping on foot with no vehicle on hand, get a cooler with a lock on it, secure it with a rope tied around it and suspend the cooler from a tree. As for dry, non-perishable foods, wrap them in a towel and suspend them from a tree. Animals may still be able to read them, but it’s safer than keeping it vulnerable on the ground, or worse, with you.
Never store food of any kind in your tent to keep animals away on a camping trip. This includes snacks. The last thing you want is an unwelcome guest barging in for food in the middle of the night. Bears love the smell of mint, so keep your toothpaste with your food.
Place fabric softeners throughout your campsite–animals hate the smell of them. Secure them in various spots around the perimeter, put some in your tent and even one with your food to mask its smell.
Keep a flashlight on you at all times. You may be able to use it to scare off any animals that wander into your campsite at night.