At what point, while driving a passenger car, will you press the clutch pedal if you want to routinely (intentionally) brake when you're travelling at high speed?

When braking from a high speed, the clutch pedal should only be pressed in the final phase of the manoeuvre, when the engine RPM has dropped significantly. This allows for the use of so-called engine braking, which assists the braking system and increases the vehicle's stability. Pressing the clutch at the beginning of braking is a mistake, as it disengages the drive, and the vehicle merely coasts on inertia, which extends the braking distance.