Tune the guitar to standard pitch
Install fresh strings if needed
Set the action and neck relief first
Compare the open string to the 12th-fret harmonic
Compare the fretted 12th-fret note to the harmonic
If the fretted note is sharp, lengthen the string by moving the saddle back
If the fretted note is flat, shorten the string by moving the saddle forward
Retune the string after each adjustment
Repeat the harmonic and fretted-note check until they match
Check all strings and adjust each saddle individually
Recheck tuning across the neck after all adjustments
Verify intonation at multiple frets, not just the 12th fret