Memorize this nine-note pattern. These notes are all on dotted frets.
The middle seven notes are the musical alphabet: ABCDEFG; and it is bookended with the last letter, G, and the first letter, A.
Play the notes in ascending order starting with the lowest pitch note, G, on the E string. Then continue playing the notes as they occur in the alphabet. A and B are the remaining two notes on the E string. Those three spell GAB. The A string has CDE, and the remaining three notes are FGA on the D string.