Keeping your foot on the brake while driving downhill. Many motorists tend to keep their foot on the brake pedal while driving downhill to be ready to stop at any moment. This leads to brake system overheating and wearing out of brake pads and discs. The proper thing to do is to shift to a lower gear and initiate engine braking, which helps to reduce the use of normal brakes. It works by reducing the speed of the engine, which means that the speed of the vehicle reduces also. The aim is to prevent the vehicle from gaining too fast the speed, especially while going downhill. Don't get scared of the noise that you will hear when you use this method of engine braking. That is pretty normal. By the way, car racers often use this trick with downshifting to slow down the car before another turn. And remember to drive carefully and patiently. As John Irving wrote in his last night in Twisted River, just because you're sober, don't think.