Learn to play the E Major blues scale: E, G, A, A#, B, D.
Play the bass notes first with the side of your thumb to create a shuffle rhythm. Rest your palm toward the bridge to slightly mute the sound of the first two strings (low E and A). Practice this with a metronome.
Add the melody over the steady bass rhythm. Use your ring and middle finger to pick out the notes of the E Major blues scale in time with your thumb.
Start to bend a few of the notes in the scale to create the delta sound. This should be a ¼ tonal bend. Typically you want to bend the G, A and B notes. Still, this is a subjective choice that you should make while improvising the melody.
Add double stops to your melody. A double-stop is two notes played together to create a harmony. For example, you can place your index finger on the third fret of the second string and place your middle finger on the fourth fret of the third string. Play those two strings in time with your thumb and then hammer on the fifth fret of the second string to add variance. You can combine any two notes in the blues scale to make double stops.