Create a classy company style. Combine your outside building design with the interior one.
Once you have an idea about the exterior design of the building you should take some items of it to create the bases of the interior design. So, for example, you can place exclusive objects and hang decorative frames on the walls; or write a casual style phrase on them.
As you probably imagine the workspace is not an exception and it also should be related to the whole design concept. Use colorful mousepads (always in harmony with the rest items), specific-shaped pictures and desks. This will complement and give the final touch.