http://www.hansrey.com/lessons/balancing.htm
Steps:
1. Locate an extremely slight slope, point the nose of your bike downhill,
and roll along as slowly as possible.
2. Find a long painted line on a flat surface, and slowly trace the line with
your tires.
3. Practice a figure eight, rolling in a continually tighter and slower
formation.
4. Pedal carefully along the length of a low curb or beam.
Tips:
"The trick is to concentrate on where you want to go, not where you don't,"
advises Hans. "If you look over the edge of a drop, you'll end up there.
It helps me if I look three to five feet ahead of where I am."