Just remember that you are the Designer with the skills to create the overall design...

I was talking with a Creative Director from a Branding company and we both agree that the client 'thinks' they know what they want, but at the end of the day you are telling them 'you can have this or this...'.

Just by giving them enough choice to feel as though they are involved is enough! Sounds harsh but too much choice is almost like offering a kid every type of cake available and them wanting all of them rolled into one!