Watch the ZZ Shuffle - Solo online guitar lesson by Jeff Scheetz from Rock Solid
A technique I use on this solo is picking with the fingers instead of using a pick. We usually think of "finger picking" as a style that is more like a James Taylor vibe than a gutsy bluesy solo. But on the contrary, playing with your fingers lets you really "connect" with the string.
You can also do some bigger intervals by skipping strings, and you can get that "snap" or "pop" type sound by really digging in. Guys like Mark Knofler, Jeff Beck and tons of great country players use this technique. I don't do it all the time, but for some things stick your pick in your mouth and let your fingers do the walking!