The beauty of a CSS design lies in what we could call the golden rule of your inner sight. A beautiful CSS design it's not a matter of technique. It has more to do with your ability of seeing your layout already finished before even starting to code it. "Can you see?": a single question that haunts the Minority Report movie from the very beginning. In this movie, seeing something is foreseeing it. In fact, Tom Cruise's physical eyes are surgically removed and replaced, so they're mere matter with very few purpose. The key thing here is the inner sight. Another movie seems to give an answer to that question: "I can see" it's the dark motto of In the mouth of madness, an horror movie directed by John Carpenter (1994).
This is something that you cannot learn from books or online tutorials and articles. This is something that you should learn from everyday life, trying to use your inner sight, your projection and your imagination to see things that your eyes, your physical eyes, are not able to see just because they got used to everything. Even if you've walked your way home every day for countless years, try to rethink it in a new way, try to observe those little details that so often have been neglected. The horror writer H. P. Lovecraft was able to make you see his scenes, his settings, his cities, just because of these little details. His books are scaring thanks to these details.
Use your imagination. See that sign on the corner? Can you imagine it as the branding header or logo for a web site? Can you see its colors, its rust? Did you notice how magazine and newspapers use colors, images, columns and fonts? Walking along the seashore, what's the most striking color that makes you feel amazed? Can you reproduce it in some ways? Try to imagine.