Watch the Diamond Blues 3 online guitar lesson by Carl Verheyen from S.W.A.T. Blues
The four principles of bending are described here: 1) Straight to pitch with no vibrato. 2) Straight to pitch without vibrato then gradually adding some as the note fades. 3) Bending directly to a note with vibrato in motion. 4) Bending with all four fingers because all of the above bending principles can be applied to all four fingers. Remember, no two vibratos from two different players are the same. It is your sonic fingerprint!