One thing that I had to do to improve my balance was to deliberately challenge it. About a year ago, I became aware that I was unconsciously flinching from certain types of movement. It's a body reflex, perhaps with a bit of a phobia attached. I wasn't completing a lot of my movements, because my unconscious was trying to stay in a "safe" zone balance-wise. The problem was, though, that it was actually making my balance worse, because it was preventing me from being able to move strongly from one stable position to the next. For instance, in a rumba box, instead of getting all the way onto my forward foot on a forward step, I'd get about 75% of the way there, then start sliding my balance sideways towards the next step. The result was that the only truly stable position I had anywhere in a rumba box was after the second Q when I brought my feet together.
This was really inhibiting me in silver waltz. Once I took my first step, the whole thing felt like one long roller-coaster ride. I didn't really consider it because, well, I just didn't know any better; I just assume that that's what it was supposed to feel like. I've written here before that I have a problem with using brute strength to overcome bad technique, and that's how I was doing my waltz; through just continuously fighting it, I was able to execute, but it was exhausting and not a lot of fun.
So I thought back to something in my childhood. When I was around 12 years old (and about 100 lbs. lighter

), one of the things I did with some of my friends was practice pratfalls. I used to be able roll down an entire flight of concrete stairs and come up uninjured, more or less, at the bottom. At one apartment complex where we lived, there was a steep grass slope where the driveway snaked around to go up a hill. We'd get up to the top of that and do movie-stuntman staged fights. The loser had to go down the hill, making it as dramatic as possible, of course. And it was a good drop, about 25 feet. Our mothers used to just about kill us for the grass stains.
So I started practicing in where, to get past these protective reflexes, I deliberately threw myself at some moves as hard as possible and actually made myself fall a few times. For instance, I'd do a waltz open left turn, and on the back steps I'd move so strongly and abruptly that I'd be teetering on the edges of my heels. Before I did these moves, I'd think about how I was going to fall if I lost my balance, and how to turn it into a pratfall: soften the knees, protect the head, don't stick your hands out. And I did fall, more than once, but I was able to do it so that I didn't get hurt. And by doing this I was able to find where the edges of the envelope are, so to speak. The only way to ever find out for sure how far you can push anything is to push it past the breaking point, and then note where it breaks. After doing it a few times, and proving to myself that I could without being hurt, I was able to start overcoming the flinch reflex.
The main benefit of this is that I can now transfer my weight from one position to the next with a lot more strength and confidence. Also, because the flinch reflex tends to oppose movement in general, a lot of my steps are a lot crisper now. For instance, I have time to think about and work on Cuban motion in the Latin dances, whereas it was too fast for me before because the reflex was slowing all of my movements down. Similarly, my rise and fall has improved in waltz because I'm not coasting through my steps anymore.