Now that you know how to find the notes on the 6th and 5th strings, and you know the two octave shapes, let's use the method.
If we play the first octave shape on the 6th string, third fret, we get two G notes.
If we play the second octave shape on the fifth fret, 4th string, we get two G notes.
If we were to slide these octave shapes up two frets, we would have As. Two more, Bs. And so on.
By applying these two octave shapes from the 6th string, we can find any notes on the 6th, 4th, and 2nd strings.