I don't know how you normally make your gravy, but this is how I make chicken gravy. It is incredibly easy and fast. And would work fine for turkey too, though I would add the onions in the last bit of roasting the turkey, maybe the last 45 min to an hour.
Prep your chicken (or turkey), and start to roast it in a pan with nice sides that is stovetop safe. Quarter an onion or two, seperate it into layers, and pop it in the bottom and sides of the pan, around/under the bird for the last hour of cooking. (this completely caramelizes and almost burns, leaving a lovely flavor to the gravy). When done, take the bird out of the pan, making sure to get the drippings from the cavity into the pan. Put the pan on one - two burners on the stove depending on it's size, over mediumish heat. Stir in flour until it gets very pasty. Keep stirring and let it cook a bit more (this gets rid of a "floury" taste). Add two cups (for a chicken, more for turkey) homemade chicken stock (I keep it frozen in two cup bags, pop the stock ice cube straight into the pan, it melts). Add a bit more flour or stock to the get the consistancy you desire. Add salt and pepper to taste.
Easy, peasy, and delicious. Takes, oh, 7 minutes? I would not recommend this direct method with duck or goose, because they have more fat than chicken or turkey, and would remove some of the fat before making gravy in that case. It should work well with any less fatty (like chicken or turkey) bird.