I use a 50 ft length of parachute cord. It also acts as my spare cord if I need a shoelace or tent cord and I have used it many times to lower or raise my pack on cliffs. Also handy for repairs.
I sewed a small nylon bag (I use old stuff sacks for material). You could also just use a small nylon bag. So many things you buy now come in a bag. I sewed on two loops. The sack is about a 5-inch cube. I put rock or several rocks inside, tie on the cord through both loops, and then hang onto the cord about a foot from the bag. I swing the bag (underhand) and let go. It takes some practice to know when to let go to get it up onto the selected limb. It is actually quite effective! The rock has to be heavy enough so the bag drops down on its own. I then use mini-carabiners to attach food sacks for a counter-balance. I use my trekking pole to get it down.
When I use an Ursack, I sometimes will hang it. For long trips when I use a bear can, I put what does not fit in the bear can in a small bag and hang it until I can fit everything in the bear can. I think the cord and bag weigh 3 oz. You could use thinner line, but since I also use the line to lower my pack, I want it thick enough not to hurt my hands.
All that said, I more often just use my bear can (Bearikade Weekender).
I have used OP (odor proof) sacks but am not sure they really work. They are quite expensive. They do have good seals, so at least you food does not get wet if it rains. Your whole camp area and you smell of food, so the bear already knows there is food around and can see a bag hanging.
Regardless of how I protect food, I make a point to camp away from heavily used areas where bear know they can get food. If I see ANY sign of bear, I will continue at least a mile farther to camp. If you are really concerned, cook dinner on the trail and then continue a mile more to camp.