Designer advice...it depends

The Washington Post just published an article entitled, Grad Design Guide. There are some great little tid bits of advice, like
"for walls, use a super-matte finish, which will conceal imperfections."
So true. Shiny paint will only draw attention to any bumps, drips, nail pops, etc in the wall surfaces.
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Notice the difference in the wall surface between the shiny stripes and the matte/flat stripes? The shiny finish really magnifies those wall imperfections.

But I take issue with one of the tips in the Paint section:
"If you paint, use one color rather than trying to find a different color for each room; that will help the overall space seem larger."
So not true. Define each space so that it has it's own unique character.
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By paying close attention to how one color flows into the next and works as a cohesive palette, you can actually make a space feel bigger by mixing up your color use.

Anyone have any great color design tips they'd like to share? What tips would you advise someone just moving into their first teensie apartment?