Give your current parents a handful of your business cards to hand out to their friends - tell them that if you get an enquiry that leads to a new child starting that you will give them a few hours free babysitting, especially useful with Xmas parties starting soon.

Stand outside your local NCT sales handing out flyers to people waiting to go in (there is always a queue outside ones in our town as they let the members in first), most people in the queue will be parents, parents to be or grandparents (or a childminder looking for a bargain) - don't hand out leaflets inside the building though, a childminder friend of mine got told off for that.

Hope some more work comes your way soon