Those pinch harmonics are a nasty thing to really master. So, don't worry if it takes you some time to get it right.
I suggest you use the search option on the forum here, and look for either "pinch harmonic" or "artifial harmonic". This subject has been brought up a lot of times, I'm sure there's a lot of info onhere already that you can use.

ps: artificial harmonic is actually not the right name for this technique, but a lot of people seem to call it that anyway