Keep your thumb soft and relaxed. It glides underneath your palm like a smooth train going under a bridge.
Finger 2 gives your hand gentle sideways momentum. Let it float your thumb to the next note without twisting your arm.
Your wrist acts like a soft cushion. Keep it floating smoothly so your hands stay relaxed during long runs.
1-2-3-4) in the Right Hand to navigate around the B / B♭ pivot point cleanly.