I found this in my drafts post list from March of this year. One of the original set I made for Jacob ripped shortly after I made it. I wanted to make him a replacement and couldn't find the pattern I had used. Low and behold I had the pattern right in my drafts. So of the sites below the first one listed proved to be the most useful. The juggling balls are a great size and shape. Oh and the reason his ripped is because I failed to put interfacing on the fabric. The interfacing is dual purpose. One, stiffening the fabric and two, preventing fraying. So if you decide to make these I recommend doing the interfacing. Now it's happy sewing!!
This site gives detailed, yet complicated instructions.
The site below has good advice on what type of fabric to use etc.
The site below has printable patterns for many different styles of balls
I clicked on this link and got this:
This site gives somewhat useless information about making juggling balls =)