Agree with Chris (Above).
Here's my 1-2-3.
1. A warm intro is brilliant - especially from a company they funded before OR missed out on that did darn well.
2. Keep answers short, but loaded to enlist questioning from them. This creates a discussion rather than a bombardment. Ask them questions and let them discover the answers about your product by leading them in.
3. Don't pitch a VC - pitch a partner who understands the opportunity and has taken a stake in something similar or ancillary.
The best piece of advice I ever got was to swim with the sharks. Go to pitch competitions, conferences, clubs and other events where they will be at. As stated above, don't pitch them but instead play the role of a colleague in the startup atmosphere.