My idea for a Yumi-fied how-to guide is this: Learn to juggle. I thought for the longest time that I couldn't juggle because of some personal deficiency. That, somehow, a connection between the two halves of my brain and my hands could not be formed and I would never be able to do it. I had watched people do it, I had even bought sets of special juggling balls (regular balls sold in a nice box) but nothing seemed to work. It seemed as though the ability to juggle was a gift possessed by some, but not me. Of course, I am a fool. I realized that juggling doesn't come naturally for anybody, there is a technique that anyone can learn and it is actually quite simple.
First, you learn to juggle one ball by holding your hands out in front of your chest and tossing the ball with a nice arch (peaking at about eye-level) back and forth. Your tosses should be as uniform as possible from right to left and left to right. This is how you learn control.
Once you have learned how to juggle one ball (shouldn't take long) you can move on to two. This is when things start to get complicated, but the old saying "practice makes perfect" could not be truer. Take a ball in each hand and, just as you did before, toss from your right hand to your left and your left to your right. Instead of passing the same ball back and forth, you'll be tossing ball one from left to right and back and ball two from right to left and back. You'll know you are doing it right when you can feel a rhythm develop (right, left, right, left...) Remember to keep the tosses under control, the balls shouldn't go above eye-level. It may take some time to get it down, but once you can juggle two balls you are set.
Here is the secret: if you can juggle two balls, you can juggle three. Once you've learned the rhythm of the tosses, having a third ball makes no difference. It goes "right, left, right left..." keeping the balls at eye-level forever. To start, hold two balls in your right hand and one in your left. Toss one ball from the right to the left and you are off.