Acquire Platinum Medals: The best way to build up your points to platinum levels is to acquire up large streaks of hits without a miss.
Acquire Scarecrow Points: Strike any scarecrow ten times in the chest; next, hit him in the head.
Extra Points from Doors: To make some extra points, shot the doors on various buildings you see. When you do, balloons will be released, which can be shot for 100 points each.