>I would add don't take fixed price work. I've done it a few times and its consistently worked out badly.
>

Absolutely! Even if you pad the heck out of your quote, you'll likely lose in the end due to all the things the customer hasn't told you or decides to change during the course of the project.

>I also work for time and materials only. But I do give my clients a reasonale idea for how long things will take so they can make an informed decision about the features that they want.