I was very lucky in that I happened to be good friends with a super-connector type person who always has people asking him for help. If you know other people who are doing consulting work, you can talk to them, if they are good they won't be particularly protective because good people always have more work than they can do.

In general, it can take time to build this up but in my experience it's valuable to see how you can help / give to others around you, and it will come back to you at some point. You have to learn to avoid the time wasting clients and people who look for you to do spec work, but after you've learned to spot them it's not so hard.