Question
Is it best to call ahead or stop by with a portfolio and try to schedule a meeting, or more of a shock and awe tactic
Answer
Don't be a salesman at all. Go in with a genuine interest of helping these people. Ask questions and give advice intertwining your product. When you go in with the attitude of really trying to get to know about their issues and giving advice of what they can do, this changes everything and people are willing to open up and talk. Works like a charm.