I just recently noted that when you begin riffing on a certain area of the guitar strongly, there sometimes seems to be an equalization of justice around the original note, or a certain random note which then becomes central, or a note which is accented midway through.

This note takes the place of the 12 spot whole note in a new mathematical formulae of octavity. If you riff above it and then below it, the sound is kind of sour and predictable around that note, possibly because we're used to hearing the 12/octave at its normal position, and as noted above, the natural 12 doesn't sound so great when you begin riffing above and below it. So keep that in mind when you're striking out on a new octave. Stay on one side to maintain distinction, or if you do go across, respect that distinction.

Notes on the 3 skinny strings: open, 2 & 3, 5, 7, 9, 11 & 12. Hit them!!
Notes on the trick string: open, 2, 4 & 5, 7, 9, 11 & 12. Hit those ones too!