I used to make a lot of broth before... It's very simple. Get different types of meaty bones from one type of an animal (say, beef) - those should include marrow bones, neck bones, and also pieces of tough meat. Cover with COLD water and put on a medium to high heat. When close to a boiling point, a lot of scum will start appearing on the surface. Reduce the heat a little and collect the scum with a spotted spoon until there is no more. After that, add veggies - whole carrots, onions and celery, and good sea salt. Reduce heat to a minimum. After about 1 hour of simmering, remove the veggies (otherwise they will get too mushy and spoil the taste of broth). Let simmer for about 24 hours - on the LOWEST possible heat. Some also recommend to put vinegar into the broth but I never do - IMO, it spoils the taste. When broth is ready, turn off the heat, let it cool a bit, throw away all bones and meat (or give those to your dog) and filter the liquid through cheese cloth. It will keep well for over a week in the fridge, or you can freeze it.
