Most of rosemary's special magick comes from its ability to cleanse and purify. Burn it to clean both the air and the negative energy from your home. Wash your hand in rosemary water before applying healing salves or lotions. Add rosemary to your bathwater to refresh your skin.
In ancient classical times rosemary was known to grow on Mount Olympus as the flower of the gods. Its powers of protection can extend to food (add it to bread, tomatoes, butter or drink rosemary tea), and health (I always add rosemary essential oil to shampoo, conditioner and lotions).
It certainly doesn't hurt that rosemary is incredibly easy to grow, drought tolerant, and is a wonderful fragrant addition to your garden.
Probably one of my most favorite of all the herbs, and that alone makes it magickal.