Find a container that will hold your goose with enough space around it to allow the brine to move freely. Slip in the goose and cover it with water, which you should measure as you add. Then, for each gallon, put into a saucepan 1 cup of salt and 1/2 cup of sugar. Add a few cups of water and bring to a boil to dissolve. Off the heat, add whatever flavorings you'd like. A blend I've enjoyed is 5 crushed black peppercorns (lightly crushed), 1/2 cinnamon stick, 1 clove, 1/4 tsp. ground cardamom, and 1/2 bay leaf, for each gallon of water. Let cool and pour into the water surrounding the goose. Refrigerate for about 24 hours, longer for a giant bird. Then remove the goose, pat it dry, and either use immediately or store in the refrigerator for up to 2 days.
Before proceeding with any roasting method, be sure to pierce the goose's skin all over with too quick thrusts of a small, sharply pointed knife. The knife must be held nearly flat to the surface so that it pierces the skin and fat without puncturing the meat. Then concentrate on areas where you see large pools of fat under the skin. Let the goose come to room temperature for 3 or 4 hours before roasting.
Related Recipe: Alsatian Roast Goose