oh, that. very very easy. Natural harmonics have an interval of 12 frets. So, if you hit an open string and touch the string directly above the 12th fret, you with get the harmonic. this will work all over the place and for every string. try freting on the first fret, and touch right above the 13th fret, same thing. I freted the 12th fret, and if you count up 12, thats 24, so touch right above the 24th fret, see? now fret the 13th fret, and touch just after the 24th fret (where a 25th fret would be), same if you freted the 14th fret, and touched a little more down. you can keep going, by either touching the string, or using the pinch method, especially after like the 16th fret.
theres also other intervals too, 5 and 7. which means on an open string, you can get harmonics by touching right above the 5th fret, and 7th fret. this is where things get kinda cool. fret a string anywhere before the 12th fret. now, while you hold down the string and its ringing out, count up 5 frets, and touch right above it, either with your picking hand, or if you want to get all cool and tricky, use your pinky on your fretting hand. now try counting up 7 and do it too. you can get them after the 12th fret, but they tend to not ring out as good.