Collecting Jokers increase value of drop targets. Try to collect 2 or 3 before working on the bank to maximize points.
Shoot drop targets to complete poker hands for bonus at the end of your ball.
Collecting Jokers advances the value of color coordinated lanes and advances the value of the saucer on the right.
Plunging for one of the Jokers is key - the red and green affect bottom lanes so go for those.