There are three rituals I know of for the changing Moon phases:

• the New Moon ritual
• the Full Moon ritual, and
• the Dark of the Moon ritual.

Each ritual will require a Leader, (High Priest or Priestess, but for simplicity's sake I will refer to them as a Leader) and a black bowl filled with water.

These rituals can be indoors or outdoors, many or few. They are adaptable to your needs. The rituals I have included here are Robin Skelton's outlines from his book "The Practice of Witchcraft". But rituals tend to vary based on the coven performing them.

I prefer to add a short Moon-gazing prayer of my own instead of casting a circle for the ritual.