Watch the Bending, Ex 4 online guitar lesson by Larry Carlton from 335 Blues
Playing blues in the key of A often lands a player in fifth position, where it's common to bend notes with the 3rd finger on the 7th fret. In the first video, let's mix it up a little and first try bending with the 1st finger (index finger) right there at the 5th fret. Bending the C (5th fret, third string) up a half step gives us C#. Notice the subtle difference between the half-step bend from C to C# and the whole-step bend from B to C# on the same string.
Now use that 1st-finger bend immediately after a 3rd-finger bend, as I do at the end of the Video 1 clip.
In the next exercise, we're playing up in the seventh position (but still in the key of A), try concentrating on more first-finger bends in the middle of your lines. Notice the difference in sound between sliding and bending up a step? Also catch how the third finger gets a little bend of its own before the line resolves.