If you're tuning a guitar with a
floating bridge, you will have to repeat one of the above processes many many times to get the tuning right. Why? If the guitar has a floating bridge,
tightening (adding
tension) to one string will pull the
bridge closer to the head of the guitar, effectively
loosening the other five strings (and
vice versa). If you were to, for example, tune your A to 110Hz and then change the tightness of the other five strings, you'll more than likely end up with an A string that's tuned to 114 or 107Hz, and five other strings each tuned against a different pitch.
So, what's a body to do? To save time, I generally tune the low E, then the A, then the low E again, A again, D, low E (starting to see the pattern?), A, D, G, low E, A, D, G, B, then finally: low E, A, D, G, B, high E.
And now I hear you exclaiming, "Geez, what a pain in the ass! Do I have to do this every time?" Luckily, the answer is probably not. Most guitars with floating bridges are also equipped with locking nuts up at the head of the guitar, which allow you to fix the tension of the strings within a certain range... imagine a capo fastened on the 0th fret of the guitar, which keeps the string tension from altering if the tuning knobs move at all. Once you've tuned your guitar for the first time (after, say, adding new strings and stretching them out), fasten down the nuts, tune your A to concert pitch, and then proceed as described in the above write-up using the fine tuning pegs located next to the bridge.