Barry Levenson here. Just got back from some great gigs in Europe, so I haven't had time to write. It's true what they say about how musicians are treated in Europe. It was a wonderful experience that all blues musicians should have, at least once in their life. Anyhow, back to my series of articles on finding your own individual style through the medium of blues guitar.
Touch is almost self-explanatory.
Picking up near the bridge creates a harder, more trebly sound. Picking near the neck creates a softer, bassier sound. In the middle creates more of a mid-range type tone. All places where the right hand can pick should be experimented with to find different sources of expression. This is another element that contributes to your touch.