Here are a couple of takes of mine, one
slide version on my resonator, one non-slide on my nylon.
My approach, as you may already know, is to take it one chord at a time, keeping the key in mind of course, but I never think scales ... I would have no idea how to improvise thinking scales or modes. The chords say it all, I follow them. Melody loves chord tones, and I love melody. If you want to know
how I follow the chords, you need to read
PlaneTalk!