Watch the Like A Woman: Ex. 4b online guitar lesson by Andy Aledort from Kings of Blues & Rock Vol. 4: B.B. King

This is another example based on "theme and variation," in that I set up a repeated theme in bars 2 and 3, and then deviate from the theme and move into different repeated themes (and variations) in bars 5 and 6, and then 7 and 8. Take notice of each of the melodic inventions, and the ways in which each smoothly follows the one preceding it.
In bar 9, over the V chord, D7, the line alludes to a chordal substitution of ii (two minor), Am7 (or Am9), which is a great sound and offers a nice twist from a standard 12-bar blues; the same is true for bar 10, as a line which alludes to D9+5 as played over C7.