Seriously not that hard, sherrard.
Have a word with your butcher or turkey man and see if they have some bones carcass....
sweat onions down with some root veg scraps and then add the bones and heat through, splash in marsala or a sherry/white wine and let that reduce....add thyme, (lemon thyme I prefer), maybe a sprig of rosemary and chervil, tarragon if you like it. Then the water and slowly reduce until you have a nice stock (a slow simmer of a couple of hours, watch the liquid level.
Sieve and put in a container(s) and you can actually freeze this.
Now a wonderful tip for the turkey - separate off the legs and crown before you cook it - the legs needs longer than the crown to roast! You can also stuff the legs with some sausage meat (seasoned and herbed).......
Keep the juices and add those to the stock for the gravy.......