Watch the Modified Eight Solo 1 online guitar lesson by Chris Buono from Guitar Lab: Blues Soloing
Look for the chromatic moments within the first and third choruses. In the first set of eight you'll see a simple walk down to the root of the V chord (C7) in bar 7 that resolves itself at the downbeat of bar 8 - classic move you MUST know. When you get to the third chorus you'll see a consecutive half step motion in bar 5 over the Gm textures and then again in bars 7-8 over the I and altered V chords to make for a very cool exit from that solo. Chromatic instances like these add a dash of sophistication to your blues soloing without overcomplicating things. If you're diggin' the sounds, good, there's more chromaticism coming your way as the course progresses.