A fundamental part of Feng Shui is the balancing of the opposing forces of Yin & Yang.
Yin is female, dark and passive, while Yang is male, bright and active. The Tai Chi symbol show the unity of yin & yang. One cannot exist without the other. Night does not exist without day, winter without summer, shadow without the sun. Similarly, each quality has an opposite such as hard and soft, angular and wavy, dark and light, wet and dry, cool and warm...
The Chinese community would say about a space that feels good to be in that the yin & yang are balanced.
In a home design, yin & yang must be balanced to create a perfect harmony.
For example, in your living room, you need to balance hard yang items such as hardwood tables, mirrors, and glass vases with soft yin pillows, curtains, throws, and rugs. If you have too many yin or yang accessories, there will be an energy imbalance.
If you have too many yin or yang items, they will be an energy balance.
A Feng Shui Designer will be the best person to not only create a space that corresponds to your personality and needs but also to balance the yin and yang accessories with shapes, textures and colors to create harmony and balance in your space.