How do you know when a new client is going to be a good client?

For all you freelancers out there … how do you know if you’re prospecting a good client?
(You know, the kind that are easy to work with, make easy decisions, pays on time.)

This might be somewhat applicable to your question: http://www.sitepoint.com/7-qualities-good-client/

If you want to find a good client it will take a time. At first its not easy to say a new client is a good client.First you have to give your time & attention to the new client, talk to the client & observe his behavior.If the client shows you very good behave & respect to your work & also you.We can say that the client may be good.I think behavior is the main think to judgement a person .

For me good client is a client who is not trying to touch everything you have just created without a fear to break the code.
Good client asks you “what is safe to do and what is not”. Good client will be happy when you add some extra pages without charging anything.
Bad client is a client who will tell you from the beginning that he hired a big advertising agency, they did his website for $30,000 and it looks like **** and it doesnt work. And your task is to redone his site for $300 in two weeks because he runs out of budget. And even if you re-do his website, he will continue to say it looks like ****. He will always ask more for small money.
Bad client will try to explain YOU how you should code his site. And he will break your code, trying to experiment with it and will call you at midnight screaming.

Bad clients you feel from the beginning.