For me being in the NYC and freelancing.. having a good network is completely necessary in order to get jobs that pay the bills.
It may sound silly and obvious, but in order to keep myself in people's minds, I see all their shows! I keep an eye on playbill, websites, Time Out magazine and when I see a show a director, designer or producer I've worked with has done I go see it (usually in previews when it's cheaper..)
Recently I applied for a job, and when they contacted my reference (a director I love working with) he got back in touch with me to say "come see my show!" so I made time to go see it, met his current SM who is booking me for more work this summer as a testament to my 'loyalty' to that director.
Also I can't stress enough the importance of networking in theater complexes--If you're working in a busy complex (for me its Theatre Row) take the time to get to know the staff, managing directors, the guy that runs the stage door, because I recently got a few one-offs because when a group came in from Tennessee and needed a SM last minute, they called me.
Just a few tips that always work for me!