Duck or goose breasts are best seared rare-to-medium, and either served with just some salt and pepper (celery salt is excellent, too), or sometimes with a nice pan sauce.
I also have my recipes for ground duck here, too, because it is really hard to get meat off a little wild duck leg to grind, so I mostly grind the breast meat of lesser ducks, like scaup or spoonies.
Here is my technique for cooking a duck breast, and you can find a selection of my wild game sauces here. Below are a few special duck or goose breast recipes; and remember you can always use domestic duck instead of wild duck, although you will have more fat to deal with.
GROUND OR CHOPPED BREAST MEAT