There is a great warmup that I have seen multiple people use:
You simply toss the ball and get the racquet up at the same time. Its basically the first motion of the serve. One pro I play does this every time before we play sets. I started doing it too, and it really works. My timing just syncs up.
The trophy pose is the wrong way to focus. It can make you stiff and ruin your motion. Just focus on that whole first motion of getting the tossing hand up and the racquet up at the same time.