For this article a short brief about improvising over an E major Blues.

Most guitar players may start improvising over an E major blues by using the E major Pentatonic Scale.
Why not try using the A major Pentatonic? The scale will give you the same A, B, C#, E, and F# notes but for some reason you may feel you do get a different sound. The E major Pentatonic does have a G#, which is the third in the scale, the A major Penta does not have this note.

As far as the sequence goes you may play: E7  A7  and B7 in any order to create a 12 bar sequence.

When you play E7 the D (7th) resolves to the 3rd of the A7 chord. Try using those notes to see what effect they will give you.

When it comes to the A7 chord you may like the sound of the G resolving to the F# which is the second of the E major Pentatonic scale.

Play around with the notes to see what they can do for your phrasing.

Enjoy and hope to see you again soon,
Eddie