Stand at arms-length from the table with the bat able to touch the table without any undue stretching.
Lightly hold the bat so that the blade is positioned slightly higher than the elbow – if it is held too tightly, reactions will be slowed.
Initially have the toes parallel to the end of the table, with the knees bent and weight forward.
Be ready to either block or smash every return.
This image from Table Tennis England illustrates it perfectly:
