Last updated on 10-Mar-2013 03:53:44 AM
The idea is to have a lot of backspin and not much forward momentum on the ball.
The brushing action should be right under the ball and even coming under and up the front face of the ball a little.
You can practice getting the contact correct away from the table. Just find a piece of floor and see if you can get the ball to come back to you on the floor. Once you feel comfortable doing this then you can step up to the table and give it a try.