How do you decide on the concept of your interior design? I ...

How do you decide on the concept of your interior design? I am currently building a house, not a huge house, and the floor plan is extremely functional. Since I was building from scratch it made sence to do the interior design at the same time, and I want it to be as functional as the floor plans. I would like the space to flow. I know what I like in individual products - I know what flooring I like, and what doors and so on, but I think to do a whole space I would need a concept or Idea to work around and am not sure how to come up with that. Any help would be more than welcome. Thanks.

Think of how you'd like to feel in this space. think about places that gives you this feeling. Can be imaginary as long as you can see it clearly in your mind. Don't think functional. Dream! After you know your dream start thinking about the details: colors, textures, objects. Make a list or draw if you can and than introduce the functional demands into it.