Feng Shui is a mechanic in Animal Crossing series based on a real world concept, though the Animal Crossing version is simplified by quite a bit. Mainly, what you do is place certain colored items in a certain corner of your house (see the chart to the right), giving you good luck. Very few items, called "special Feng Shui", will give you luck no matter where you place them in your house. Feng Shui is the main contributor to points to the Happy Room / Home Academy as of City Folk.
Many items don't have Feng Shui value, though ones that do generally are either yellow, red, orange, or green.
Special Feng Shui
As mentioned above, some items are Special Feng Shui, which means they'll give you luck no matter where you put them in your house. Obviously, these items are rare, and ones you certainly don't want to blunderingly give away. A full list of Special Feng Shui items can be seen below.