There's no real "breaking in period" needed. Take it out and shoot some rounds of clays with trap loads, just to get used to and comfortable operating and shooting it.
For ducks early season I might shoot #2's fast steel and improved cylinder choke over decoys. Later season and bigger ducks I go to #1 or even BBs fast steel for mallards/pintails (bigger full plummed ducks) and usually modified choke. 3" loads for ducks.
Geese I always shoot BBs fast steel and 3 or 3.5" loads. BBs do the job in fast steel out to 45 yds in my experience breaking wings and penatrating to the vitals. Any bigger than BBs and the goose down with ball up and get stuck in the breasts, unless you happen to break wings or hit heads.