For years, I used to do quite a lot of in person networking at chamber of commerce events and such. The key is to remember is that unless someone asks you what you do or wants to get a detailed list of your services, it's purely social, and so you need not be intimidated or feel like you need to be selling yourself.
Yes, it's good to have a 5-second elevator spiel, but you can relax and just be yourself without worrying that you're in the spotlight.
What do you do when you want to buy a new car or find a new babysitter? You ask your friends and coworkers. When people need business services, they ask theirs. Getting to know folks and allowing them to get to know you is really all it's about.
Many times, people would forget what exactly my business did, but they knew I was a wiz with computers (I was a web designer at the time), so they would call and say, "Do you do any work on Macs or know about Outlook? I might have a project (or referral) for you," and I might not be able to help them, but they'd remember next time that I was the website lady in their Rolodex...and once they remembered, they'd send me all their website referrals.
Because I spent time talking to so many folks and becoming interested in them and vice-verse, I stayed top of mind for a lot of people, and they'd eventually remember what I did, and word of mouth referrals started to just come naturally. It doesn't even matter what it is you do, if people like you, they will call you when they need help or possible project work.
Another thing I did a LOT was connect other people together...because I was a busybody and talking to everyone. So whenever someone wanted to perform some task or had a question about something specific, I usually had an expert to refer to them. I did that a lot, actually, without sometimes even thinking too much about it.
PS - don't forget any expenses you put out for these over the year are a cost of doing business and you can (usually) itemize them under marketing.