So there are naturally occuring harmonics on frets 5, 7, 12 and so forth. Take string 6 (E). Want to shift a harmonic so it now plays on the 14th fret? Simple. With your fretting hand, hold down F# on fret 2 of the low E string. Simultaneously, you must now use your picking hand to pluck the note (I use my thumb) and produce a harmonic on the 14th fret (I use my index finger). Is this making sense? When you've got this technique down, you can create artificial harmonics in any area over the fretboard and do some wacky stuff.
Hope this helps...
Let me know if you need more explaining...
:)
Matt