Put simply, the more people you know the more chance you have of doing business. So, for many, networking events are the place you go to meet more people. However, don't make the mistake that so many others do of expecting an immediate return. Successful networking is all about relationship building and this takes time. So, find a networking group, commit to go there for a period of time and get to know your fellow networkers. This starts with taking their business card when you meet them and writing to them afterwards saying it was good to meet them. So many people don't even get this far and instead their desk if full of little piles of cards that eventually get thrown away. Connect with them on social media and let the relationship flourish.
Remember, that everyone is there to find more clients so do your best to find out exactly what people are looking for. Bringing them contacts which might turn into business is the key to the group doing the same for you. As soon as you become known as a lead generator people will want to do the same for you. Making introductions is the simplest way to develop your network. Most importantly, when you are given a lead make sure you follow it up before your next meeting so you can give feedback.
Most events require you to do a brief presentation about your business. This can be daunting initially but just explain what you do and what sort of clients you are looking for. With time you'll become much more relaxed and can then vary what you say. Try to be topical and not to serious. You need others to engage with what you're saying so make sure you stand out but be careful not to cause offence.
The strangers you met on your first visit soon become people you know reasonably well and the forced conversations you had at first will become much more comfortable as you discover common interests. Networking really can work, you just need to persevere.