It kinda depends on whether you are hunting puddle ducks or diving ducks.
Puddle ducks tend to want shallower water and generally a more “marshy” environment. Diving ducks like wide open space and the depth of water isn’t a big deal for them.
When I go to a new lake I start by looking for ducks…no point in setting up in a part of the lake they don’t normally use.
Once you narrow that down then I look for points or island that have decent cover to conceal you without having to build a blind.
It is always good to go out there and check spots out first hand in the daylight, something might look great through binoculars but when you get there the cover is too thin or so thick you can’t get a boat in to it or the water may too deep for decoy cords.
Something else that is good to try and find is an area where there is only 1 spot with cover for a long ways….it will prevent people from setting up right next to you.
Islands and points tend to be the best spots in general.
JB