Don't over call. Calls are most useful for calling in single birds or isolated pairs.
Do not begin shooting while birds are still landing. For maximum shooting opportunity, wait until birds already on the ground begin to get nervous and take flight.
Hunting partners should agree on fields of fire so shooting opportunities are not wasted by shooting at the same bird.
Take your first shots at birds that are at the fringe of your effective range, then work your way back through closer birds.
Focus on one bird at a time.
A morning's shooting ends when the birds go back to roost in refuge areas during the middle of the day. Sometimes that is as early as 9 a.m., other times they may not roost until noon. Afternoon feeding flights can arrive two hours before dark, but they may not appear until shooting hours are almost over.
2 3/4-inch shotgun shells with No. 1 or No. 2 steel shot work well for snow geese.