never go into first gear
only go into first gear when you are stopped
if the vehicle is moving, the lowest gear you should select is 2nd
again this would be from sub 30/40km/h
you dont need to downgear in sequence but dont go from 4th to 1st or 2nd
theres too much ratio difference. if your in fourth and slowing down, goto 3rd and brake a bit
use both to slow the car down. not one. if you stick with using one (ie engine or brake)
when you need to emergency stop you wont clutch in, which will mean the car wont stop for peanuts
in an auto when you brake, the engine is disengaged from the clutch, so you stop normally
if you do the same in a manual ,the car will pull up heaps slower and take much longer, cos the engine and clutch are still engaged. ie like slowing down a spinning wheel whilst someone is still pedaling behind on it (on a bike)