I have won a few jobs, but I only now bid for things I feel I have a good chance of winning. I have bought a lot of services on it; SEO, VA support, presentation production & PR mentoring.
I would echo what VirtualAssistant says about having a presence on there. I am now an Associate of an org we connected on there.
I used to do marketing in the charity sector. It might be worth contacting charities similar to your old employer to see if they need freelance help? I am guessing lots of them will be up for the flexiblity of a freelancer?
I have posted here before quite a while ago now but forgot my username and password details so have a new user name now. I use people per hour, it took 2 years of bidding before I won something!! But since then I have had a couple of people contact me 'directly' and I have secured some work this way with one person becoming a regular client. It is worth using if you have the patience to finally win some work!