E7 chord. Here’s a variation on your stock standard E7 chord. It will add to your Blues playing.
The regular way of playing E7 is to lift your third finger off an E7 chord. Sometimes that does not add much to the sound. First of all you might not being playing that string if you are using a constant bass note. Secondly, if your fingers are not upright you are not going to hear the difference between E and E7.This form of E7 has a higher sounding D note in the chord. This is known as a different voicing. Notice how the D sound jumps out when you play it.
Try it with a Bass, Up, Down, Up, Bass, Up, Down, Up strumming pattern. BuDuBuDu. Count it 1 a2 a3 a4 a. This is a shuffle or swing rhythm.
The E7 chord often goes well with the A7 chord with the G on the first string.
Try moving between E7 and A7.
Finally try a Blues progression with these chords,
E A7 E E7
A A7 E E7
B7 A7 E B7