Do you mean artificial or pinch harnmonics? I guess it's just semantics, anyways.

Anyways, i assume you mean pinch harmonics. For me, i find it works best with my strat set to the bridge or middle pickups, or with the neck pickup with its tone set to 10.

Turn on some distortion, and pick the string downwards so that just after the pick strikes the string, your thumb lightly touches the string. It should be a very subtle touching, not as if you're picking the string with your thumb, but just like a sweeping type motion.

Try it and i hope that helps.