Let your taxidermist decide what looks best. He can decide what pose looks best as the bird comes together. There is always one side of the duck that looks better than the other. If you had a hardmouth dog that put his chompers on one perticular side for example, and allowing the taxidermist to guide your duck to completion with a pose that would suit your specimen the best, is much easier for the taxidermist when he isn't inhibited by your perticular preferrence. On the other hand, if you have an absolutely perfect specimen, (very few holes in it, no broken wings, not licked to death by the dog, not chomped on by a hardmouth dog, not freezer burnt, not half rotten, an adult bird, no pinfeathers, and in full color) then your taxidermist should be able to capture the perticular pose you're looking for. You can see that there are a lot of things that can hinder the integrity of that "perfect mount", so please understand that the taxidermist is the pro, and the hunter is usually overlooking at least one impefection. Ask any taxidermist "what is your worst bird to mount?", and he'll probably respond with something like an opening day Wood Duck shot in September. To the hunter, they can't help but look at this ultracolored beauty of a bird, and to the taxidermist they are looking at a thin-skinned, pin-feathered, nightmare!
My choice? Wings cupped, feet straight down for the landing, and the head at half cocked, with the bill looking for the landing pad. You know the look, right before you shoot it in the lips!