I save all the bones and skins from my whole cooked chicken. I save them in a couple of ziplocks in the freezer. When I have enough I throw it in my biggest pot, add whatever veggies I have in my freezer scraps bag plus lots of carrots, onion and garlic skins, celery, etc. Add water and vinegar, soak for 1hour, bring to a boil, and skim the scum.
Here's where I get a little crazy. I add several sections of dried astragalus, dandelion, burdock and echinacea root along with handsful of rosemary, thyme, oregano, parsley, nettle, and several bay leaves. This I bring to a rolling boil, give a good stir and pop the lid on. Drop to lowest setting and simmer for around 24 hours.
Cool, remove fat cap, put in glass ball jars leaving LOTS of headroom if you want store in the freezer. I find that we go thru a lot of stock each week so I just store in a 1/2 gal ball jar in the frig. If I have excess at the end of the week then I reboil, cool and freeze accordingly.
This makes the most delicious and immune boosting stock you can imagine. This way of making stock was taught to me by herbalist Susun weed. There is an article about it on her website.
NOTE: Many people find they get a better gelatin if you take it off the stove at 12 hours, pop in the frig over night and simmer again the second day for 12 hours. I have done this and it does work but that is a lot more work.