I asked what sort of duck just due to the differences of a pasture raised duck and a wild one, however I’ve found that the classic approach is best for me on both.
I like a light cure of salt and sugar along with any aromatics you choose and lemon zest. (for wild duck legs obviously not too long on it, 3 hours produced what I like) and up to 24 hours for large duck legs. Confit is the way after rinse, and a slow braise at that, 300-320° .
I like to do a similar dry brine on the breasts, just a few hours before cook. The backs I’ll sauce up. Cooked about 16 mallards this way since Xmas eve.