When practicing you should always take time to work on balance and be aware of it when doing techniques. Good balance is essential for doing effective striking combinations, footwork, throws and counters. When I say balance I mean in all of your actions and movemesnts not just while standing in a stance. One common way people lose their balance is over committing to an action. In fast footwork even if you need to come to a sudden stop or direction change, you should still maintain a balanced stance (this means weight centered between your feet or if on one foot directly over it don't let your momentum pull your weight over your toes or heels). Another example is that you should not commit to strikes so much that you lose your balance if you miss. Also practice on different surfaces, grass, rocks, hills it's easy moving across a gym floor and staying balanced but you need to be comfortable in any environment.