Watch the Bmin Blues online guitar lesson by Larry Carlton from 335 Blues
Let's have a look now at developing a chord solo over blues changes. For this example I'm combining chord changes with an improvised melody. There is always melodic content so it's not just about throwing out a bunch of cool sounding chords.
One way to get started is to play a single-note line - start with a short phrase - and then consider how that line might be harmonized in the context of the prevailing changes.
See the PDF for a full transcription of how I took that idea and expanded on it in this clip.
Although you're going to see a lot of chords pass under my fingers, there are no tricky changes in the progression. The whole thing is based on Bm blues (Bm - Em - F#7).