A great way to simultaneously learn the fretboard and generate unpredictable, almost random sounding phrases is to play wild scale patterns that move up and down the neck on two strings. A great place to start is with patterns that go back and forth between two adjacent strings. One cool pattern I came up with along these lines is this one [Ex. 1].
I’m playing in 4/4, but, thanks to the pattern’s grouping, my line sounds angular and almost like it’s in an odd meter. The faster you play it, the wilder it sounds. The general feel is sixteenth-notes—one-e-and-a, two-e-and-a, etc.—but the scale pattern repeats every 14 notes, creating a 14-against-16 sound—or a 7/8 against 4/4 sound, if you prefer to think about it that way. In other words, in 4/4, the phrase repeats an eighth-note sooner each time—and, you’ll notice, one degree higher up the scale, which is how the pattern carries you up the neck. Based on the E Aeolian/natural minor scale, the first 14-note cycle starts on B, the next on C, the next on D, etc., as shown.
Once you’ve got the pattern down, learn it descending as well [Ex. 2]. Then, try it on the other two string-sets—the first and second strings, and the fifth and sixth strings. (This pattern really wails on the high strings.) Last, but not least, try these patterns in different keys and with different scales. That’s when, in addition to creating that explosive sound everywhere on the neck, you’ll really start learning the layout of the modes up and down the fretboard.