How to hang food using the counter balance with retrieval cord method.
Pick appropriate tree and branch. In bad bear areas a proper tree may dictate where you camp. As you near timber line there may not be tall enough trees, so you must plan ahead. The limb should be about 20+ feet from the ground. Higher is better as bears are less likely to jump off a limb onto the bags if they know they will take a long fall. The bags should hang about 10′ out from the tree. Where the rope goes over the limb, the diameter of the limb should be about the size of your wrist or smaller. Larger and they can climb out the limb, smaller and they can break or chew through the limb. Some bears can get any food hang too. Check with local authorities about food storage methods. Food hangs work best with wild bears that have some fear of humans.
Camping with groups, we had to hang as much as 200 lbs of food each evening. It can take several hours, and several trees, to do it right for that much food. A bear resistant canister may be a safer and easier choice for some folks.
Hear are some custom food hang bags by Oware. Ultralight silnylon and noseeum net made for BackpackingLight.com, and heavy Cordura ones made for various Outdoor Schools.
Note the bright orange throw sacks for holding a rock when setting up, and the cord when not in use. Orange is easier to find if you have a bad throw.
The heavy bags use a reflective loop on the bottom (for a retrieval cord) that can be quickly seen at night with a flashlight when checking for suspicious bear like sounds.