Forehand Volley with a Continental Grip
You mention “power” and “offense”, which are both somewhat “forward leaning” visualizations. On a forehand volley with a continental grip, you must resist the temptation to hit the ball too far out in front of you. You should hit it more by your side, no farther forward than your leading knee. If there is ANY “forward” visualization that would be helpful, it would be that of a “leading” elbow, which should be pointed downward and positioned ahead of the racket during the preparation. This will, by the way, be difficult to do if your body is leaning too far forward.
Many players, and even some coaches, seem to be obsessed with forward motion in their quest to gain power. But they sometimes don’t consider the negative impact that blind addiction to forward movement can have on posture, positioning and technique. On the forehand volley in particular, I would advise focusing on the shoulders being up and away from the ball, even if it means having to lean back at times, so that the proper distance from the ball, elbow attitude and volley technique can be maintained.
Also, while waiting for the ball and remembering to not hit the volley too far out in front of you, be sure that the racket head is positioned higher than the level of the approaching ball.
MG