The proper way to use nitrous is to inhale deeply and hold it in.
Seriously though, as long as you have a decent ignition and fuel system, and you don't pick an outrageous nitrous/fuel mixture amount you can't really go wrong. Running an eleventy billion shot of nitrous in drakkie's shitbox for instance is just not a good idea.
BTW, Nos is a manufacturer of nitrous oxide systems and components (as is NX and ZEX). Not the nitrous itself. Noob.
EDIT: Can't this f****** thread just die already?