The Back Sweep is also done in various ways. You can start off with any technique. In this video I started off with a step, slap, and double palms. When performing the "Back Sweep" kick, make sure you drop into a "Pu Bu" drop stance first and then swing the sweeping leg around with the toes pointed and always keep the sweeping leg straight. (Please pardon the dark video!)
* Tip - Your foot should always touch the floor and you should hear your foot scrape the floor.