First, in the morning or afternoon, stuff all of your bones into a stockpot and cover with water. I literally jam all the bones in--as many that will fit. If you have leftover gravy, you can add it now, too. I then simmer this on the stove for many hours--5 or 6. Add more water when needed. I then let it cool for an hour or so and put this whole pot into the refrigerator. I sometimes put it into a large container with a lid before putting it in the refrigerator. The reason for putting it in the refrigerator is so that the fat will rise and you will be able to skim it all off.
The next day, pull out your pot of broth and bones. Use a spoon and skim off all of the fat. It looks like hard butter. If you don't get it all, that's ok. A little fat in your broth makes it better. Most of the broth at this temperature looks like jelly. Add some more water and heat again on the stove. Depending on how much time you have, you can let this cook again for more hours--but remember to keep adding water. When you are ready to clean the meat off of the bones, remove from heat and drain into a collander or strainer.
It seems like a long process--but it really doesn't take too much hands-on time. The broth and leftover meat that you save are like free! I know that many people throw this broth opportunity away. Give it a try if you haven't yet. If you do this kind of thing--are there any tricks that you have used?