A good way to develop good alignment in motion is to throw and catch things as you walk. Do it by yourself in front of you and continue to do this to the sides and from the back to the front and so on. If you have a partner to do this with it is great but it also works as you do it by yourself. Remember to pay attention to the breath and the alignment (you can even place a stick in your shirt to keep yourself aware) and pay less importance on the catching of the object.
