[stlcards08]

You must clean your grooves after every shot! I never used to clean them at all, so I never got backspin. Ball would release and roll a few yards. The grooves were all filled up by the time I could make good contact. Before golf tryouts one year, I decided to clean my clubs. To my surprise, the ball stopped immediately upon hitting the green. Your grooves also must be sharp. When I got my new clubs, I even began to bring the ball back some on my PW and 9I on those rare occasions that I actually hit the green.
I don't know if this helps or not, but my Grandpa had me hit balls off of a 2x4 once. He said it would cause me to create backspin, I guess because it would force me to hit ball first or else the ball would bounce off of the board before my club hit the ball.
I would also imagine it would take a fair amount of swingspeed, since fuller shots result in more backspin. Green conditions and lies also play a factor I'm sure.