I agree with the general synopsis that it is better to not have the markers on the guitar. That said I will tell you that I did add a marker at the 5th fret of the Takamine when I got it. It was my 1st classical guitar and I began my journey to learn on it. I placed a small dot on the top rim of the fretboard using White-Out, the type repairing fluid used by secretaries and every person who ever had to complete a paper for turn-in at school. After it dried I touched it with clear finger-nail polish to harden it. It was quite a nice dot and I only just flaked it off to ensure that when I tell you it is not permanent and will not damage the finish I am speaking from my own experience. My other guitars do not have the dot and I've been concentrating on learning all of the notes on the fretboard which makes it unneeded. Of course you need to learn specific positions on the fretboard so another useful thing to do is to learn the 7th fret by heart. If you know the 7th you easily know the 5th and 9th. Learn the 7th by making it a point to play the harmonics for each string at the 7th fret and the 12th fret. Do this by lightly touching a barre at the 7th and 12th fret and gently exciting the strings which I do by making a brushstroke off the top of my "m" nail. By comparison of the tonal quality of the harmonics this is very useful for knowing how well your guitar is tuned when you 1st pick it up.
I had to correct my discussion about harmonics. It's the 7th fret you compare not the 9th.
Last edited by James A. Showalter on Mon Mar 11, 2019 4:12 am, edited 1 time in total.
1972 Morris No. 12
1972 Ryoji Matsuoka, No. 18
1973 Ryoji Matsuoka, No. 20
1990 Takamine C132S
2014 Sakurai Kohno Pro-J
Martin Guitars (D28, MC28, D12-28, J40)
National Resonator Guitar
Les Paul 1960 reissue