I use the pan that the drippings are in if I can. I try to take out as much oil or fat as I can till there’s just a little bit left. Add water and bring the pan drippings to a boil. Get all that fond pulled together. I use a few spoonfuls of corn starch that I put into a small bowl and add water to make it look like whole milk consistency. I furiously stir in the corn starch water while the pan drippings are working their magic. Add salt and pepper to taste. Sometimes I need a lot of salt, other times not much. Pepper gives it something that it needs. Once in a while I will add herbs, but not usually.
It is probably years of watching my Mama and Grandma make great gravy that I learned how to do it. It’s an eyeball kind of thing. I don’t have specific measurements for any of those, but if you get the corn starch and water mixture to the consistency of milk first, it usually works out ok. Sometimes I have to quickly make up another batch of the corn starch while it’s cooking to get it right. Add more hot water if you get it too thick. It usually evens out in the end.
That sounds like the way my grandmother did it. It was always in the roasting pan after the bird had been taken out.