The concept is the base of your design decisions, without it, it would be very hard to make choices, to follow a path, to go in one direction. Concepts make our life easy and take us gently to our aesthetic objectives.Make good concepts because they will lead you to nice results.
Here is mine for a hotel in Shanghai.
This is how it ended up looking when pinned up and ready for presentation.
All the images (except my sketches, of course) were taken from the magical world wide web.