Here was my first try:
I wouldn't say it was difficult but it is a little fussy, and maybe moreso because I'm using slightly stretchy piley fabric. Still, I really love the results. Even when the corners don't meet up so nicely. For the first ball I sewed the first three pieces together and then the second three pieces, and then the two halves together. It worked out okay, but on my second try I thought I'd sew each new piece to the ball, rather than doing it in halves. The benefit of doing it that way is that the corners pretty much have to meet. Sadly, you've got to do a little more sewing by hand to tuck them all in and it's not particularly easy hand-sewing. I'm not sure which way will be my default.
I stuffed these with polyfill and put a little sewn up sandbag in the middle so they wouldn't float away. I'm curious to see if they can survive the washing machine. If they survive the washer and a few weeks of play, you may see some of them in my shop.
Here's my second try:
You can see that my hand-sewing is a little wonky. I was surprised how nice my seams tuned out where I stuffed though. I used some advise from Keyka Lou to stitch them closed. Some of it didn't really apply to obv, but her method worked nicely anyway. I'll definately be using it the next time I'm working with wovens.
I hope I get around to trying this one, too!