One of the best pieces of advice I've heard regarding networking is "If you want to be interesting, be interested." People are much more likely to remember what they said and who they said it to than what was spoken at them.
When you engage in conversation with someone, be genuinely interested in what they're telling you. Find out what they are trying to accomplish and what their obstacles are. Think to yourself - "How can I help?". You don't have to immediately connect it to your business. First help come up with suggestions or solutions, then see if there's a way to connect it to your business. Even if you can't, your help will be greatly appreciated and remembered, which is excellent PR in and of itself.
Every conversation is an opportunity to learn something new. With the price of higher education spiraling ever higher, it would be foolish to pass up the chance to absorb valuable information and insights for free. Think of conversations as idea exchanges and make sure you walk away with more than you came in with. Of course, by offering truly valuable information and insights in return, both parties walk away wealthier.