Safest thing to do is shoot orbits to get back up to the top, in hopes of entering top saucer again and again, which is key (like Xenon).
Inlanes drop the center post.
Center stand-up target raises the center post.
Don't use the upper flippers to shoot the drops, it's an easy way to lose control. Hold the flippers up to keep off the slings instead.
6k and 12k awards from the saucer light left loop and right loop rollovers (to increase bonus) respectively.
Left and right drop target banks each increase bonux X when completed.