Oh yes, you heard me right... were going to talk about the fine art of pimping

Im now involved in a game project that im very excited about and for the first time deserves a bit of hardcore pimping and i was wondering about the tactics of some of you FK'ers...

When is a good time to start pimping a game?
How much information do you give away?
What about screenshots and demos?
Do you find it even helps at all?!