You say you hunted geese. Ducks are similar to hunt. They have their roosting areas and feeding areas. If you burn the roost, they dont come back. Similar things with feed. You can run traffic on them for better consistent success. Jut like geese if you are "on the x" you wont need very many decoys or call much. If you are in between roosting and feeding areas or cant get on the best spot but are close, larger spreads will be better. If you are lucky enough to be out there when the migration is on hunt larger water/rivers with larger spreads. Even though many ducks will land in mallard decoys you will generally have better luck with specie specific decoys. It is amazing how much better they work their own over mallard decoys only. If you find a water hole holding puddlers and geese, I would opt for goose decoys over duck decoys as puddle ducks do like to play the decoys well. Lots of videos out there about calling and decoy placement but not a lot about where, when and why to hunt a particular spot. The old days of killing limit after limit in the same spot just isnt a reality anymore. Scouting will be needed to have consistent success.