After you have practiced the three ball cascade enough that you can do it comfortably, you are ready to learn your first juggling trick.
Over the Top edit
The first trick that most people learn is "over the top". This trick is just what it sounds like, instead of the normal cascade throw in which the ball travels under the previous one, you throw a ball over the top of the other one.
To begin with, practice the over the top throw with only one ball. Simply take the ball in your hand and "scoop" in a half circle towards the outside instead of the inside. When doing this you will probably want to move your hand further to the outside in order to make the throw more horizontal. When doing this you should throw the ball all the way from one side to the other whereas in the cascade you throw them from the middle to the outside.
Once you are comfortable with this try working it into a three ball cascade. Do not worry about it falling. Just throw it over the top of the other balls and resume your cascade.
Jugglers' Tennis edit
Before you learn this trick you need to know "over the top".
When doing "juggler's tennis" it may help if you have one different colored ball but it is definitely not necessary. The jugglers' tennis is when you do an "over the top" over third throw such that the same ball goes over the top every time you throw it. If you have a ball that is a different color than the other two that should be the one that goes over the top. This will help you to remember which ball you are supposed to throw over the top and lets you concentrate more on the technique.
Half Shower edit
Before learning this trick you need to know "over the top". "jugglers' tennis" will help but is not required.
In the "half shower" you throw ever other ball over the top such that the same hand always makes this throw. If you thoroughly practiced "over the top" and "jugglers' tennis" this should be fairly easy.
Reverse Cascade edit
Before learning this trick you need to know all previous "over the top" tricks.
This trick is basically a cascade where you throw every ball over the top of the others. It is not, however, that simple. You see if you throw every ball with the over the top throw, you will have to continually throw them higher and higher until you cannot keep up. Instead, you must make your throws go from the outside to the middle. This will be hard at first but with practice will gradually become easier.
As soon as you have the new throw down you will want to work it into the cascade. You may have been starting with a normal cascade and working your way into the trick before, but with the reverse cascade you will have to go straight into it. You may not get it at first but keep at it. You will get it eventually and it is really fun once you do.