How To Play An Insane Guitar Solo

What's the most insane guitar solo you've ever heard? One by Paul Gilbert? Yngwie? Eddie Van Halen?
If you're going to play an insane solo like the guitar heroes, here's what you need to start getting good at. These guys didn't learn this stuff over night! Let's get that straight up front. Shredding, especially shredding not just up and down scales, takes years to master. Not just that, but these guitar gurus are always pushing their own playing to the limit in their recordings. You can imagine the difficult road you have ahead of you.
32nd Note Legato Runs
At some point during the insane solo, most of our favorite guitarists will play abnormally fast, 32nd note legato runs. This will be the fastest, most impressive point to the “lay person.” We guitarists know shredding is much harder, although slower.
It's important to develop legato techniques (all hammer-ons and pull-offs) along your 3-note-per-string scales and Pentatonic Scales. You'll want to skip strings, do amazing finger stretches, and of course, full neck legato runs. Listen to Joe Satriani in particular and you'll hear all kinds of crazy legato sequences.
Finger Tapping
For the most insane solo, add finger tapping, as pioneered by Eddie Van Halen, though brought to a whole new level today. There's 2, 4, 6, and even 8-finger finger tapping. For the most dramatic effect, learn 8-finger finger tapping and not just on the upper register, more like the middle register and upper register combined. Be sure to tap arpeggios as well as be inventive in your note choice. The greatest taps are created with “worldly sound” in mind in my opinion.
Shredding
Get your metronome and start increasing your speed until you can play 16th notes at roughly 200 beats per second. The insane guitarists don't only shred up and down scales at this speed, but also sweep arpeggios and Pentatonics at this speed. Get a book that teaches you all of the arpeggios, not just diad.
Tetrachords
Throw in tetrachord runs. Tetrachords require intense finger stretching. These are essentially 4-note-per-string diatonic scales. Type “tetrachords” into a Google search and there you'll find what you're looking for. Charles Gacsi at WholeNote has a great lesson on the theory behind tetrachords.
Guitar Face
As if it weren't enough just to play an insane solo technically... You need to develop a guitar face worthy of the masters. No simple facial expression will do. You must practice this in the mirror, coming up with an original guitar face.
Tension and Release
Don't be afraid to go outside your comfort zone and experiment. Even by hitting “the wrong notes” you're doing something right. You're creating tension. Use Chromatics to create tension or rip some notes off a bizarre scale for tension. Because it will be released to create a great feeling of contrast in your listener once you begin playing in key again. For the best release, only a simple melody will do. A simple melody repeated on and off within your insane solo will make it a memorable one.