Watch the Dirty Blues 5 online guitar lesson by Carl Verheyen from S.W.A.T. Blues
The major 3rd of the E7 chord is a G# and by bending up to it we get a nice bluesy start to the solo. Then I bend into b7 of the IV chord which is a G natural. The second chorus takes it to another place but I follow the same concept by bending into the important guide tone.