One of the best free camps I have stayed in is on the Putty Road, halfway bertween Richmond and Singleton.
At the Grey Gum Cafe you can stay for 48 hours free. They have nice clean amenities, hot showers for a fee, campfire drum and the food is excellent.
They make the best BLT I have ever tasted. Kim and John run the place like clockwork.
At dusk you can feed the kangaroos that come out of the bush.