Brakes to slow and gears to go
Interesting points above about downshifting as you slow down a car with manual transmission. Being British, I learnt to drive a car with a manual gearbox and was told to shift down through the gears as I slowed down.
I recently read a short article on this subject in The Daily Telegraph, (electronic version). It appears that the 'downshifting' technique stems from the days when car braking systems weren't as effective as they are today, drum brakes versus disc brakes, etc. The author stated that the British DSA,(Driving Standards Agency), now teach the use of the footbrake alone when reducing the speed of car, then selecting the most appropriate gear for the speed the vehicle is going. This is the technique which police drivers are taught, and that which the dreaded driving examiner looks for! This technique is known as Brakes to slow and gears to go.
I must say that I still downshift while braking!, (old habits die hard).
As an aside, the brakes-only approach is what I was taught in the USA when taking motorcycle lessons. Downshifting was for experienced riders only, apparently.