I can hear it now, builders proclaiming loudly that it isn't their fault the ray gun app failed and killed everyone in sight. THEY were only building the steering mechanism app to quicker target the peasants trying to run away. Clearly not their fault.

Overheard in Warp Lounge 7:
Crap, so we have to wait ANOTHER half billion years for the sun to correct this colossal mistake called "earth".
Let's give them ZPM's and watch them fumble and blow up...

1. Make sure your client understands that changing a website core mid development will make it push past scheduled completion time AND drive the costs up. Sign contract (talk to a lawyer to get correct wording etc).
2. Make sure they understand that changing website mid dev... yeah.
3. Written communication each and every time or you will be SOL when the client decides to change the website mid development... you never win an argument with a client unless it is all documented.
4. Quote them a whole project if you feel they are willing to cough up the cash for it. Take deposit totalling no less than your expenses (eg. travel, lunches, new software, etc)
4.1. If they state during initial talks "Pricey/too much/whatever GAH" quote a base site, (text, images, pretty banner maybe even a basic flash animation or 2), then each addon priced separately.
5. Make sure they understand that a lot of the work is behind the scenes, but show them the pretty to satisfy their visual urges.
6. Be prepared to age quick.
7. Know people are relatively clueless and needs basic stuff explained again and again. Write it down in an easy to understand format and email to them. Keep it short, most clients develop a severe form of ADHD when they need to make an effort to understand you.