I find it amusing that your (edenecho) picture is of the word tilt. But you don't like to move the machine, causing it to tilt.
Tilt is the game telling you to calm down. It you can shake the cabinet and have it not tilt; then you've done it properly.
I think the best advice I've heard is that you can't affect the ball. The ball will roll where the physics will take it. When you nudge the machine you're trying to move the Playfield under the ball. The game will tell you if you've gone to far.