Dave Wirth
One of my first teachers, Jason Werkema, had an awesome way of learning how to play a classical guitar piece with the right amount of tension. Simply, he would try to play so light that he would buzz each note. This is a brilliant strategy. It worked great to ease tension, and he played his pieces quite flawlessly. Since he was aiming to sound bad and buzzy in the pursuit of the right amount of tension (in practice of course), he also managed to import the visual piece of the song. When a guitarist eases up, the emphasis is tremendously visual.
Guitar is an appealing instrument to the eyes, as far as I am concerned. Why else would we be so enamoured with how cool people look when they play it? The techniques of learning to play a difficult piece with the eyes could be just as good as with the ears. The funny thing is that by aiming for it to sound bad, we gain an appreciation of how our fingers look as we play.
Try this out: Find a song or piece of music that has a passage that is a little bit more difficult than what you are ready for. Then, tune your guitar in an awful, random, tuning. Finally, aim to buzz each note. I mean it: Every single note should sound buzzy and out of tune. Since it will sound bad, you'll be forced to look at the sight-lines of where your fingers are more than hear the result. If you can stand playing your music this way, the look and feel of how your fingers do the work will be fascinating. Perhaps when you tune your guitar back to normal and play it, you'll find that your ability to play the difficult passage has been enhanced.
Voila. Looks good, sounds good, more fun. Two great tastes that taste great together (Thanks to Mike S. for hipping me to The Bad Plus covering Radiohead's Karma Police, with pretty much the same words).
