Various hints to get you started

Colored cups net you more points if you drop balls in them, and the balls will change color. Then you can drop the colored balls in clear cups for still more points.
Don't try to fit too many balls in a single cup, since that makes your drops more difficult.
In later levels, with too many cups, sometimes it's best to let some pass so the screen doesn't get too busy.
The more balls and cups you can keep around, the easier it is to keep your score growing, so only give up cups when you need to.