Bast, or Bastet was the Egyptian goddess whose domain included cats, war, protection, family and music, worshiped as early as the 2nd Dynasty (2890 BC). Her main center of worship was the city of Bubastis.
Bast was thought to be the same as Sekhemet, another cat deity from Egypt. Similar deities like these two usually converged, however these became two seperate deities. While Sekhemet ruled Upper Egypt, her centers of worship was more focused on Lower Egypt. Bast took on the role of a domestic cat, while Sekhemet gained the head of a lioness.
In her cult centers, many mummified cats became unburied, as the death of a cat was cause for great mourning. Upwards of 30,000 cat mummies have been found when her temple in Bubatis was excavated. She also held the honor of one of the most joyous festivals, with greek historian Herodotus reporting over 700,000 people in attendance. This featured drinking, singing, dancing, and general merryment.
She was honored as an Eye of Ra, a protector of Egypt, and is often featured battling A/pep, a snake divinity who represented all evil, destruction, and chaos in the earth.
One of the most important things to remember in honoring Bast is her domain. She was, first and foremost, Bast, not the deity of anything, like how most Greek deities are recognized. She was seen as her own force, and her domain included ways to honor her, things she liked, and things she protected. As such, honoring Bast is to honor a whole, complex person, and ask for her protection.
To do so, you can adopt a cat, volunteer at a humane society, play or create music in her honor, upkeep your home, and, as always, offer up food or drink in her honor.