Gears - simplified!

[iggibizzle]

Why do some people over complicate things, If its hard to pedal change down, If its easy change up. Just ride and enjoy it.

This!

 

[Puddles]

Why do some people over complicate things, If its hard to pedal change down, If its easy change up. Just ride and enjoy it.

Or for me...

If its hard to pedal change down, shout at the small child behind you to pedal!

 

[Browser]

One golden rule for me is that speed of gearchange with a deraillieur-equipped bike is dependant on how fast your cranks/wheels/legs are rotating. In other words if you're pedals are going round very slowly and you need to change gear it will take ages as the chain has to roll offone sprocket onto another, and if you're shifting the front i.e. from a larger chainring to a smaller it will take an age as they are larger diameter.
Short version, make sure you change gear before you slow down too much as it will take far too long and put you at risk of falling over sideways.