I wouldn't start on any particular part of a job until they have made up their minds on it. The way my luck goes, I would get it finished to a certain point, then they would decide on something that would require me to demo some of my work. I'm sure if you explain it to them that way, they'll make up their minds pretty quick. As long as you're making progress, I'm sure they'll be happy, but when your progress slows or stops, they'll realize they need to get with the program.
Just make sure you get the change order signed after they make up their minds.
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The top ten reasons to procrastinate:
1.