For starters, if you are eating wild duck it should be cooked all the way through. I know some will probably oppose me on this, but there is a MASSIVELY HUGE difference between a duck that is farm raised and one that is taken in the wild. I am a medium rare kind of guy but I always cook my wild game all the way through. If done right it will still come up tender and delicious.
1. Soak it in some Game Tame marindade -
http://www.allegromarinade.com/renowned-marinade-favorites/game-tame-marinade - this stuff is simply awesome. It goes great with Venison too, but its probably good on anything.
2. Wrapping in bacon is a great way as well. To up the flavor, soak in some Italian salad dressing 24hrs before wrapping and cooking.
3. Duck butts - Cut duck in to smaller chunks. They can then be marinated in Game Tame and thrown on the grill. Another way is to throw some butter and minced garlic in a fry pan on a lower heat setting. Don't go too hot or the garlic will burn. Once the butter has melted and the garilc has let some of its flavor off throw the duck butts in the pan and cook until done.
4. Butterly Breasts - Butterly the breasts so they are twice as big but twice as thin. Melt butter in a pan on medium heat. Toss in equal amounts of onion and green pepper to cover the bottom of the pan completely. Once they have sauteed and softened lay the butterflied breasts on top off the veggies. Bring the heat down to a medium low and cover. Turn halfway thru the cooking process. By the end the veggies should be reduced quite a bit and you should have a nice jus to top with.
5. The Classic Crockpot - Cut breasts in to chunks or leave whole. Combine in a crockpot with whatever flavor Cream of "___" soup you wish. Some times I even mix flavors. My wife and I both seem to like Cream of Onion and Cream of Mushroom w/ roasted garlic. Set on low and cook until done. I like this one because I will set it when I leave for work and by time we are back home it's ready to eat. My mother always flours and browns in a pan, but I usually skip that step.
Those are just a few that I took off the top of my head. All of the above recipes are for WILD duck. If you notice, there is a trend of cooking slower on lower heat to keep the meat moist and tender. The approach to cooking a farm raised duck is going to be quite different because it is usually only taken to medium rare at the most. You can probably still do the same recipes that I have posted here but the cook times will be less. I have never had farm raised duck. I grew up on the wild stuff and have cooked it myself many times. I would like to try farm raised duck sometime, but I can't bring myself to spend the money on it when I have it in my freezer year round from hunting season.