You could try and memorize each piece of information as a mnemonist. That would be, extracting all the information to be memorized and create patterns to identify and memorize such with images and the method of loci.
This is overkill and probably better not to do:
For instance: number of fret (1-14), string (1-6) and note name (1-7 alphabet) would be a piece of information to be memorize. Just 72 notes. That you can identify by numbers of pairs, instead of 1,2,3 you think of, 01,02,03…, now each note will be the equivalent of a 6 digit combination: fret - position - note. And there are patterns to help you memorize the notes faster:
fret1 - position1 - note(Alphabet to numbers)
fret1 - position2 - note(//)
fret1 - position2 - note(//)
fret1 - position3 - note(//)
fret1 - position4 - note(//)
fret1 - position5 - note(//)
You will have 14 of these, and simply memorize the numbers, as numbers, then recall giving it the meaning they have.
Obviously, you could already notice that this is overkill and more work than needed, after all, the fret and position is not what you want to know, but that in the fret-position, there is a particular note.
This should work:
Use the image loci method or dedicated loci method:
1
Use a loci for the fret and position, select a room, or object or whatever for the fret, on this Fret loci you now select a within/on/around but in tandem with or to this Fret loci, six positions, this then will be the Fret-Position loci.
2
Now place on your Fret-Position loci each note with a particular image.
This method is also good to memorize language grammar, consider that all the cases of the nouns for Russian can be memorized within 18 loci. The use of peg should be made whenever it reduces work.
For the notes, I’d use a alphabet peg for the notes and nothing more but the technique. This I have not tested in this particular case.