The 531 is the most basic of the "tower" patterns.
These tricks are characterized by the descending height of each
throw (until the pattern repeats). This trick looks decent—though the other
tower patterns look better—but is a pain to learn.
Taking a close look at the trick, we can see that there are three throws: a high throw (5), a low throw (3), and a horizontal pass (1). We can also see that the highest throw and the pass alternate balls, while a single ball is used for the lower throw.
It is best to begin learning the 531 by practicing the high throw and the pass. Start with two balls in your dominant hand. Throw one ball high across your body, and immediately make a horizontal pass to your other hand. Then, using that ball you just passed, you are going to make another high throw across your body, and then catch the first ball you threw. Then, pass that ball and repeat the cycle:
Practice this pattern until you have it solid. These two throws are identical to the ones made in the 531, and the third ball fits into the space between them. For the next step, you are going to practice making that lower throw. Start with one ball in each hand. Make one high throw, and then make a lower throw (less than a normal cascade throw) with the other ball. You want to time these throws so that the second ball (low height) lands in your hand slightly before the high throw:
This is an important step. The timing of these two throws must be consistent, or your entire pattern will fall apart. Once you have the previous steps mastered, you are ready to put everything together. Start with three balls—two in your dominant hand, one in your non-dominant. Throw one ball high across your body, then a low throw from the other hand, then immediately do a pass from your dominant hand. Using that ball you just passed, make another high throw (going the other way), and repeat the cycle:
You have just done a full run of the 531. It is very important that you practice both sides evenly, as running the trick for any length of time will require many throws from both sides. The 531 is not an easy or pleasant trick to master. The timing will feel rushed and awkward at first, and the trick itself is only somewhat pleasing to the eye.