Normally when stopping, leaving the engine in gear, drive, second or low, helps slow the car down. When it gets to the point that the engine has done its part then disengage it via clutch and press the brake peddle. Just a simplistic answer to the role of horsepower and brakes. Of course one has to be aware to let the engine do its part before use of brakes. Emergency stopping may necessitate slamming on the brakes and then immediately tending to the clutch, etc.

Best,

Charlie computer