Any tuning method using octaves is correct in principle.  There are many variations and one way is to tune the open B string one octave below the 7^th fret B on the high E string, the open G string one octave below the 8^th fret G on the B string, the open D string one octave below the 7^th fret D on the G string, the open A string one octave below the 7^th fret A on the D string and the open low E string one octave below the 7^th fret E on the A string. To avoid errors further up the fingerboard, make your comparisons using only fretted octaves between the 7^th and 12^th frets, and try tuning in this order:

1. Tune the bass (low) E string two octaves below the treble (high) E string; With the treble E string tuned to a reference note, tune the 5^th fret harmonic on the low E string to match the open treble E string.
2. Tune the D string to the (in-tune) treble E string; compare the octave between the 7^th fret B note on the E string and the 9^th fret B note on the D string.
3. Tune the G string to the (in-tune) treble E string also; compare the octave between the 10^th fret D note on the E string and the 7^th fret D note on the G string.
4. Tune the B string by comparing the octave between the (in-tune) 7^th fret A note on the D string to the 10^th fret A note on the B string.
5. Tune the A string by comparing the octave between the 7^th fret E note on the A string to the (in-tune) 9^th fret E note on the G string.

If you tune all the strings to the same reference string you can avoid a small error on one string affecting the others.  For example: Tune the 5^th fret E note on the B string, the 9^th fret E note on the G string, and the 14^th fret E note on the D string all to the open high E string (which has been tuned to a reference pitch).  Then tune the 7^th fret E note on the A string one octave below the open high E string, and the open low E string two octaves below the open high E string. 

Then check that the 5^th fret harmonic on the low E string sounds the same pitch as the open high E string. (Since octaves are pure intervals, we also can tune using the octave and double-octave harmonics – above the 12^th, 5^th and 24^th frets.)

Fine Tune as follows:

• The A String: Tune the 12^th fret harmonic on the low E string to the fretted 7^th fret E note on the A string.
• The D String: Tune the 12^th fret harmonic on the A string to the fretted 7^th fret A note on the D string.
• The B String: Tune the 12^th fret harmonic on the B string to the fretted 7^th fret B note on the high E string.
• The G String: Tune the 12^th fret harmonic on the G string to the fretted 8^th fret G note on the B string.

Finally, check that the 12^th fret harmonic on the D string sounds the same pitch as the fretted 7^th fret D note on the G string.  This is an extremely effective guitar tuning method at getting the best available results out of a poorly adjusted instrument.