Actually, these days the only way I roast a duck is on my indoor rotisserie. No smoke, no greasy spattering, & a juicy, crisp-skinned, nearly fat-free bird. WONDERFUL!!! Don't know how I managed all these years without it. I'm only sad that it's not quite wide/long enough to do a goose.
If you are roasting one in a conventional oven, I suggest you consult Julia Child's The Way To Cook & follow her steam-roasting method. I use it every Xmas to do the holiday roast goose, & just like rotisserie cooking, you end up with a juicy, crisp-skinned, nearly fat-free bird.