When to shift gears? 2011 MINI Cooper S
 

I have a 2011 MINI Cooper S with manual transmission. I just bought the car a week ago. I used to have a regular mini from 2006 which was also manual transmission.

At this MINI gathering I spoke to a man that is on his 3rd cooper now. He says that I'm shifting gears to early and likely to get carbon buildup if I don't start shifting the right way.

Apparently the MINI needs to be shifted at higher revolutions. Does anyone know what the ideal RPM is that I should be shifting at?

thanks