Making gravy in my family is an art form. My grandmother, mother, aunts, daughter... we all do the same thing, yet each one's is a little different. I think it has to do with the age of our cast iron frying pans and the way we fry off the seasonings.
A traditional Sunday meal, or "company" meal was usually a nice roast, rice and gravy, (and the gravy is a side-dish, it takes just as much prep time as anything else), some kind of vegetable au gratin, some seasoned vegetable, salad, french bread and dessert.
My grandmother used half oil, half flour, but I've cut the oil waaaaay back. In a large cast iron skillet, I heat the oil, almost to smoking. I've done it so much I know when to put the flour in, but sometimes I hold my hand over the pan to 'feel' the heat. Once I add the flour, I stir constantly, making sure to get the sides and bottom until its the color of dark chocolate.
All the veggies have to be chopped ahead of time, because if you don't add them right away and turn the fire down a bit, the roux will burn.
In general, I use two large onions, chopped, one bunch green onions, chopped, 3/4 bell pepper, chopped, two celery stalks, chopped, four large toes of garlic, chopped, either one fresh tomato chopped or a couple of tablespoons of tomato paste. I add these vegetables, one at a time, starting with the onions, and cook until clear, then adding the next... the garlic and tomatos I add last so they don't burn.
Once the roux is well cooked and all the veggies are clear and limp, I add stock, (beef stock or chicken stock, depending on what the gravy is for), about four cups, or until the gravy is the right consistancy, with a little extra water. Then I add the chopped herbs, basil, oregano, parsely, one small bay leaf. I let it gently simmer for about an hour, adding water if necessary. Salt and pepper to taste.
About half way through the cooking of the roast, I add the gravy to the wonderful pan juices. For a turkey, I add the gravy after removing the turkey from the roaster.
Both of my kids are grown and out of the house, but when they visit, or I visit them, this is usually the requested meal. I got a kick out of my daughter last Christmas while we were visiting, she asked me to make the gravy for the gumbo... and while I was cooking it she sighed in ecstacy and said... "no one makes gravy like my mama".

How do you make your gravy?