Just remember, you don't have to be able to juggle all this to juggle 5 balls cascade.
These are just helpful recommendations. 

And here is how I did it ...

How I learned to juggle 5 balls. 

This document describes how I learned to juggle 5 balls.

First Let me emphasis that this is how I did it, it worked for me , and it probably will work for any other person. But there are no rules.
Second, there is nothing new in it, just the way I did it.
A little background:
When I started working on 5 balls I could do the following :
            3 balls cascade.
            3 balls shower – both ways.
            3 balls flash.
            4 balls fountain.
            And a bunch of other 3 balls tricks.

I could not do :
            3 balls snake (chase).
            4 balls tricks.
            4 balls out of 5 cascade (55550).

I started working on 5 balls on 5/2002.  I got to 35 catches in 8/2002.
Here is  the detailed progress:

Thanks to Scott Seltzer for sending me his ‘overzealous excel sheet’ to track my progress down.

Now how I did it:

First thing I practiced was high 3 balls cascade. I tried to make is as study I could, not moving my feet, trying to catch the balls always in the same place.
It was a little boring, so I did not practice this ‘trick’ a lot.
After it I tried doing 3 balls flash (high throws, 333355500). Again trying to make is as study as I could. I also tried clapping hands in the holes, or tapping my legs.
After a while I tried doing the flashes continues. This was a little more interesting, but also much harder. I could do the flash, but usually I had to move my hands to catch the balls.
Then I worked on 3 balls shower, both ways. My right shower was much better than my left ( I’m right handed). I tried making the shower higher (51). And again trying to be study and not move around. I was doing ok with my right hand, but it was very difficult with the left hand.
While practicing all this I read the excellent article about learning to juggle 5 balls.
It helped me a lot. I was also lucky enough to see people juggle 5 balls almost every week. Since I started going to the Pardes Hana juggling club meeting( Formerly the Kfar Vitkin club).
I got a few good tips there too. Thanks to Yanai to show who showed me how to start.
Thanks To Uri Yurman how helped me continue, and thanks to Shahar Kamai who helped me improve.
I tried doing the snake (chase) but found it almost impossible, I also tried 4 out of 5 cascade (55550), and it was very difficult too, I could only do a flash.
So I started trying the 5 balls cascade itself. It did not take long to get my first 5 balls flash. The problem was to improve from there.
What helped  me a lot was to start with 5 balls in my hands, do 3 balls cascade, then a 3 balls flash and continue with the 2 other balls into 5 cascade.
I did it for a few days, and found it was much easier for me than the regular 5 balls start.
When I could do 7-10 catches regularly  I returned to the usual way , start with 3 in right hand, 2 in my left wand thro them one by one.
From this point on it was just a matter of practice.
Every few days I broke my record, doing a few more catches. I also felt more in control. When I had my ‘long’ runs, 10-20 catches I could see the pattern of the cascade. I had a few runs when I felt : ‘I’m actually doing it ‘.
I know I still have a long way to go with 5 balls cascade ( and off course with  juggling at all).
I just thought to write this down before I forget it, and maybe it will help someone.

Alon 

I think I wrote that in August 2002, when I got to 40-50 catches.

Finally, here is a video of me doing 5 balls cascade.