Here’s a helpful list.

It tells you what veggies are good for stock and what to avoid and why. Use whatever carcasses you have. Break them up so you can fit more in the pot. If you are using rotisserie chicken carcasses, be sure to add all the good juices they come with and whatever seasonings you like. I tend to make it pretty generic because I can add specific spices when I use it in a final recipe. I strain it, toss the solids and pour the stock into sterile jars and seal them. Let them cool and then store them in the fridge.

I usually just do carrot, onion, celery (rough chopped), the carcasses (2 should be good), a bay leaf, 1 tsp of salt (optional - you can add salt to whatever dish you use it in), and 1 tbsp of whole peppercorns. Cover everything with water. Let it rip on low for 10 hours, strain carefully as it will be hot, portion into 1qt deli containers, and freeze.

Here is the reference recipe for chicken stock for canning. It's very basic. I like canning because it is shelf stable and even with a chest freezer I'm careful with freezer space. My chicken stock is more like this. This recipe has not been tested for home canning. I can it anyway but you have to make your own decisions about testing.

I've had excellent results with a similar recipe from Chef Jean-Pierre.

Lots of people save veg scraps for stock which is frugal and reduces food waste. If you use onion peels your stock will be darker.

In a slow cooker, ten hours on low works well.