I've been a guitarist (off and on) for 30+ years, and I'm oddly fascinated by tuning methods and practices.<p>The best educated guitarist I've ever known (he was an LA studio guy who moved back to my home town to raise his family and was teaching at the high school for fine arts I attended...literally everyone here has heard songs he played on, and probably a few musicians he's taught) used a technique I haven't seen very often, but it's been my favorite method. It's based on chords and the naturally occurring "beating" when intervals in chords are "right". Basically, you're switching back and forth between perfect fourths and fifths across all the strings and finding the best balance between them; when the beating is minimized, your guitar's first position is about as well-tuned as it can possibly be, given the limitations and oddities of intonation on a fretted equal-tempered instrument and the different sizes of strings. This is how I tune, unless I'm going to be playing way up the neck, in which case I tune with an alternate further up the neck to accommodate that position better.<p>The interesting thing about this, and the thing that always confused people who see me tuning is that overdrive/distortion makes this method work <i>better</i>, not worse. It exacerbates the beating and makes it more clear when you're tuning it right.<p>James Taylor devised a system that accommodated the way lower strings tend to rise in pitch when strummed aggressively; he'd tune a tiny bit flat on the low strings, getting close to on-the-nose as you went up the strings until the high E was exactly right. You would adjust this method slightly based on gauge of strings and whether the G string is wound or not. In this way strumming hard wouldn't end up sounding sharp on the bottom and out of tune across the instrument. This seems like a pain in the ass, to me, since you need a tuner and to memorize the settings across the neck to get it exactly right, so I have only done it as an experiment. I couldn't hear a positive difference compared to my usual method of tuning with chords (which already accommodates the sharpening of low strings because we're tuning to chord shapes).<p>A common method I've seen maybe most often, especially among metal guitarists who tune down and bass players is the harmonics method (5th and 7th frets of strings next to each other). This has the benefit of bringing the tuning notes up into a higher register where our hearing is more accurate. Distortion doesn't hinder this method either, so rock guys can do it without changing their amp settings or whatever. But...and this is a big but. This isn't actually a great method for getting good tuning, because it will be the natural harmonics of the strings, which <i>aren't</i> exactly the same as the notes on an equal-tempered instrument. This was the method I used when I was a kid. The traditional fifth fret (and fourth fret) method, that is the first method most guitarists are taught, is still better than this one, because it accounts for equal temperament.