ness, shifting bike gears is much like shifting car gears, everyone has a different style. While driving, I shift to a higher gear when the tachometer reaches 3500 revs, but you'll drive the same car and shift at 4000 revs each time. It's a matter of choice.
With the bike it's almost impossible to "copy" someone else's shifting. There are so many factors and variables that come into play, like fitness and strength levels, your muscle composition and the way you train.
You will need to find a rythym and cadence that you are comfortable with, whether riding uphill, on a flat or going downhill. Most humans have a "frequency", and even if you force yourself and ride at a higher or lower cadence than you are used to, you will soon enough be back to your "frequency" cadence without you even knowing it. Thats part of our genetic makeup.
You need to find a "frequency" with which you are comfortable maintaing for sustained periods of time. If you are happy hammering the flats in a high gear (small gear at the back), and you can maintain that for kilometer after kilometer, then thats your "frequency". If you start feeling uncomfortable or struggle to maintain your pace, then you need to shift to an easier gear to bring yourself back into synch with your "frequency". Same with climbing. Climb at a cadence or "frequency" that you are able to maintain, and shift gears around that.
Anyway, thats the way I see it.