clients who change their minds at a moments notice

it is funny as i have seen clients come and go, the clients who stay trust the creative.  the ones who leave don't.  they are constantly changing their mind.  and then they don't understand once they have approved a piece of work, it goes through the rigorous mechanical stage of work, where everything is made perfect, which costs money.  then after all is said and done, it is sent to the printer and they have worked it up in their software.  at this point the client has an Epiphany and says we need to scrap it all.  but they don't want to pay for it all, not having realized all of the hours that go into finalizing an idea.  well it is too late now, and kind of funny to us.  good luck with trying to get free work for 40+ hours.  getting back to really good clients, we have a meeting with mor beverage this week.