I agree with the balance ball suggestion. However, I also have to say that a lot of the balance I've learned in skating is simply from being told by my coach HOW to align my body. I would never have known that just from practicing balancing on my own. For example, in order to keep your weight over the balls of your feet while skating, you need to keep your chest over your knees over your toes, with your back a little arched. In order to keep your weight over your right side (in a backspin, for example),you need to keep the right shoulder back, the left arm in front and the left hip closed with the heel of the free foot in front of the shin of the skating foot. There are also specific body positions for forward crossovers, back crossovers, 3-turns, etc., to keep your body aligned and balanced correctly.