I've been making bone broth for a few years now and have usually made HUGE batches to can. This year I've been doing smaller batches in the crockpot. My methods are similar to what's listed but with a few differences. Also the recipes I use for each are similar but with few differences.
For Beef......
2 or 3 lbs of beef bones, preferably the feet and/or marrow bones, either raw or leftover cooked
1 onion quartered
3 or 4 celery ribs, including leaves....cut in chunks
6 or 8 cloves of garlic, peeled & cut in half
2 or 3 bay leaves
capful of Apple Cider Vinegar, preferably raw organic with the mother (this helps to leach out the minerals in the bones)
Roast the bones in a 450 oven about 15 minutes or so till browned & sizzling. Put bones in the cook pot. Add veggies to any drippings in the roast pan to wilt. Add to the bones in pot, along with the bay leaves & ACV. Enough water to cover the bones and fill the pot. Turn on the heat to boiling, then lower to simmer. The longer they simmer the better the broth. I have left mine in the pot for up to 3 days.
You can let it cool, then put in the fridge to get cold. The fat will solidify on the top and is easy to scoop off. Then strain off the wasted veggies & bones and use the remaining broth for recipes.
For Chicken.....
2 or 3 lbs of chicken (or turkey) bones, either raw or leftover cooked....chicken feet, if you can find them are a great addition (just don't look at them if it bugs
you

)
1 onion quartered
3 or 4 celery ribs, including leaves, cut in chunks
6 or 8 cloves of garlic, peeled & cut
capful of ACV
Roast the bones & feet in a 450 oven about 15 minutes till browned & sizzling. Put bones in the pot. Wilt veggies in roast pan drippings and add to pot along with the ACV. Fill pot with water, (gallon?) bring to a boil, turn down to low to simmer for a couple days. When you've got it right, the broth should congeal (like soft jello) when cooled. And the bones should crumble to mush when pressed. This is the only time I feed chicken bones to my dogs and they love it. Strain off the broth to use in recipes & toss the spent bones & veggies or feed to pets.
If you want to, you can even make your own ACV. It's really simple, but you have to guard against fruit flies. I've made it about 3 times. The last time I gave up because of the flies.
Apple Scrap Vinegar