I've run across several videos that teach a basic golf swing using a grass whip and, while many of you will probably laugh at this, I used a grass whip when I was younger (my dad used to have one) and the principle is sound. This particular video from instructor Shawn Clement is one of the better quality ones that I found.
Take a look. It's pretty self-explanatory.
Basically, a grass whip teaches you how your arms and hands work during a golf swing. If you watch, you'll see that Shawn's lower body is working exactly as you would expect, but you don't think about your lower body. What you think about is the hand action that swings the whip, and the leg action happens automatically.
The motion is very similar to the video of a sand shot made by using the Carlton Dance that I posted a couple weeks back, except that the action is more vigorous. Both are great ways to learn what a basic but sound golf swing feels like.