It's critical to network in situations outside your comfort zone, otherwise your skills might erode.
Here in Silicon Valley, it's pretty easy to network. People are very casual and open, and if you're an investor, it's even easier. People constantly seek me out because they want me to invest in them, or to introduce them to other investors. I'm smart enough to realize that I'm taking advantage of structural factors, not my winning personality.
The real challenge, especially for entrepreneurs, is to network with your customers. No one feels the need to butter up a prospective vendor; if you can win your customers over, then you really are demonstrating your skill.
I recently went to an event where I was an outsider; the people there were potential customers, but definitely didn't want to be sold anything. If you can build relationships under those conditions, then you do have a valuable skill.
Don't wait until it's make or break; as with anything you do, networking is a skill that improves with practice. Seek out challenging situations so that when the time comes where you have to go into such a situation and get results, you'll be ready.