String of ten printed cloth prayer flags. The practice of hanging prayer flags goes back thousands of years to the Bon tradition which pre-dates Buddhism. It was a shamanic medicinal practice to help bring balance to the ancient elements that the colours of the flags represent. It is said that this balance can be achieved both internally, bringing health to mind and body, and externally by bringing harmony to the environment.  In fact the Tibetan word for prayer flags is Dar Cho, “Dar” means to increase life, fortune, health and wealth. “Cho” means all sentient beings. 
After some time the prayer flags will naturally fade and fray, symbolising the passing nature of all things, they are deliberately not hemmed. When that happens, the flags are traditionally burned to carry their blessings to the heavens and then replaced by new flags that contain our renewed wishes. Alternatively, you may simply put new ones over the old ones.
Prayer flags can be hung both inside to increase harmony and spiritual awareness or outside (the higher the better) to benefit the environment and all beings touched by the wind. It is important to treat prayer flags are treated with respect as they contain sacred text and symbols. When hanging the flags it is also important to have the correct intentions: “May all beings benefit” rather than something self-motivated: “I will benefit.”