Shawnell Priester did a very cool environment design tutorial, which will teach you how to build things faster and more efficiently.
The tutorial covers a wide variety of topics, including the choice of theme, use of composition and layout, tips on environment construction and the creation of flow. Together with the tutorial, you will get a full ready environment!
Shawnell Priester also has a number of other tutorials, which can help you build different high-level hard-surface stuff.
This thing is not free, so be ready to pay $15.