First I almost always soak in Milk or buttermilk for a day
I usually marinate in one of two marinates, sear in a hot pan and bake in the oven till medium rare.
Marinates are
1 - equal parts red wine and yoshidas teriyaki sauce and add some fresh rosemarry sprigs
2 - equal parts Olive oil and Worcestershire sauce and add some salt pepper and garlic
Both are very good the #2 marinate tastes like steak to me and you can cook it just like one
The biggest secrete is, and I cannot stress this enough, DO NOT OVERCOOK it. It will taste horrible if you do.
I have also made duck fajitas and enchiladas that go over very will with people who are not as partial with duck.