I talk to people the way I usually do, I'm quite chatty; however, I'm not programmed to 'exploit' encounters, and I don't suck up - I am quite honest and worry sometimes that I may come across as critical, or as an up-start, but some people also respond well to things I say that I think maybe a bit controversial.
For example, I went to a department to ask for some teaching work and they really messed me about, asking me to wait outside the door for ten minutes (which is fine) and then not seeing me after 40 minutes when I had things to do and people to see etc. They were quite abrupt about it, explaining I had to wait because i didn't have an appointment; so I let them know I originally agreed to wait for 10 minutes, and had to go - which I did.
I tend to follow up if there is a natural flow to the conversation that I would like to continue, or if someone asks me to. I doubt very much I will ever do some purposefully designed networking plan, I don't think I would be able to be convincing. I am one of those people who shows everything on their face...