This is a great video on balancing created by The Anaheim Ballet (via BalletScoop):
I like the way they illustrate pushing down while pulling up - the one thing I always tell my students. This can be hard to visualize, so I am going to share this video with my students and see if it helps!
The other thing they didn't really touch on is focus - I find that when I tell my students to focus on something that is eye-level instead of looking around, they are able to balance longer. Then as you get better at balancing, you can challenge them to move their head while balancing.
What are you favorite balancing tips?