A blip of the throttle when gearing down is rev matching...bring up the speed of the engine so when you let the clutch pedal out you save wear and tear on it. That's all.

You should use your brakes to slow down, not your clutch. Way cheaper to repair.

I'd save the double-clutching for driving a big semi. lol:cheers:

A lot of even experienced track drivers think a toe and heel helps the synkromesh, they will even toe and heel for every downshift in the same corner with the clutch depressed all the time. Rev matching can also be accomplished by applying throttle as you release the clutch. I find it much more dependable than a toe and heel.

That is an option.
The point of heel/toe is to give you braking and downshifting at the same time while rev matching