Comment by beat

For guitar nerds, there's a whole online business by a guy named Troy Grady about fast picking techniques (he has a ton of extremely polished videos on YouTube - start with whatever "Cracking the Code" videos are up). He decoded the seemingly-magical techniques that allow players like Yngwie Malmsteen and Eric Johnson to play at what feel like impossible speeds, and illustrates them. (tl;dr the core trick is "pick slanting", striking the strings at an angle so the pick goes in and out of the plane of strings, rather than across it, and then switching strings only when the pick is "out". That, and "chunking", breaking into units of fixed length on a single string and using the fixed length to do a clock reset on the beats).

For a guitarist, it's almost impossible to explain the myriad tiny details that go into something as seemingly simple as picking a note. Troy's analysis of instructional videos by great players, where they obviously don't understand what they're doing, is kind of amazing. And a real eye-opener, for those of us who have played a long time.