I had a client over my shoulder all day today. I'd like to share some take aways.

Know your script. Don't fumble about.
Only make suggestions when you are not getting the feedback you need. Sometimes that jump starts the clients ideas.
Never make suggestions that cant be done. No jokes.
Stay with what you know.
Be ready to translate plain English into a group of nodes.

Last a tip of the hat to all the commercial artists, client based compositors, colorist. It exhausting.