Proper gear shifting

[ravelcop]

Hi guys!

I just like to know the proper shifting of gear with regards to when to shift to a higher gear and when to go back. I'm tired na kasi of hearing other people say that they do it just by listening to the engine. I know that it should be based from both km/h and rpm guages, im just not sure how.

I also heard that gear shifting contributes a lot to fuel economy. Can anyone explain this also? And what could be the negative effect if you're not doing it right?