When you are dealing with a client and you suddenly see red flags (complaining about price, wants to micro-manage, etc.), how do you tactfully say "no?"  I don't feel comfortable in lying and saying I can't because of a made-up reason.  I need to know how to say I won't, in a professional way of course.  Do you have a generic "canned" response?  Or, do you give details why you won't take on their request?

Thanks!

This is such a hard one.  I have had some difficult clients that turn into the best advocates for my business.  But I think it is ok to be honest and say that you don't feel that you and the client are on the same page and that you think she/he should look for a different decorator.  However, if the event is close or if you have accepted a deposit you may end up with an angry customer.
 

If you can bow out gracefully and use the "I book on first come first deposit paid basis.  Regrettably, I am no longer available for your date."

If you want to be honest:  "After a great deal of thought & review of our correspondence, I feel that I may not be able to fully meet your expectations regarding this specific cake.  Please accept my best wishes."

"I cannot do justice to your requirements" says enough...more than they think;)

Thanks for all the replies and suggestions.  I'm hoping I won't have to use them too often :)