If you're driving slowly, approximately below 10mph and want to stop then press the clutch first so that the car doesn't stall and then the brake to stop.
If you're driving faster than approximately 10mph, brake to slow down and then press the clutch about 2 car lengths before stopping to prevent stalling.
Always remember that any time you need to drive slower than about 5mph then you need to press the clutch or the car will stall.
But you don't need to press the clutch every time you brake. For example, if you're slowing down for a bend then you'll just need to release the gas pedal and brake if necessary.
If you press the clutch unnecessarily or too early then you'll make the car coast or free-wheel, this reduces the amount of control you have of the car and you could increase speed.
Clutch control.
If you're driving between 0 - 5 mph then you'll have to use the clutch to control the car at very slow speeds. This is where you can raise the clutch to the biting point to make the car move forward slowly. Or slightly lower the clutch, about the thickness of a pound coin to slow down.
You can use clutch control anytime you want to drive very slowly. You'll still have to use a little gas to help the car not stall.