Prepare with the racket held high, use your non-dominant hand for balance, and generate power primarily through core rotation rather than excessive arm swing.
This offers excellent insights into perfecting your overhead preparation. The coach uses a fun analogy to help you visualize keeping your racket high. Understanding the difference between arm swing and core rotation for power is crucial and explained well here. They also touch on how solid preparation helps disguise which overhead shot you're planning to hit. This can definitely elevate your game at the net.
