I think you've got your technique a little confused. Artifical harmonics are sounded like natural harmonics, but on fretted strings instead of open ones, so, you have to sound them with your right hand instead of your left. Try playing a natural harmonic at the twelfth fret of the low E string, then, finger the first fret with your left hand, and let your right hand index finger lightly touch the string over the 13th fret and pluck the string with your thumb. That is an artifical harmonic. They can be sounded on any fretted string by touching and then plucking the string excactly one octave higher from where your fingering it. I dont know where you got that other technique from. Once I was running a Bon Jovi tune with a band and I went to do some palm muting and I was too far away from the bridge, and I got some funny noises by accident, but those aren't artificial harmonics. I just mentioned that cause it sounds like what your doing.
As for your trouble with getting pinch harmonics, there are two things.
1) Your new to doing them, so if you keep at it they'll come with time.
2) Your picking in the wrong spot. Try moving your pick around and seeing where they come best. I find they sound the best right over the rhythm pickup, put using the lead pickup and lots of high gain distortion. Remeber that where you fret the note will change where you must 'pinch' to get the harmonic.
When you get really good at pinch harmonics,(and you will if you practice them a lot) you can move your pick to different locations as you 'pinch' and get different pitches of pinch harmonics. Thats an excellent trick, and sounds awsome two!