Purification of Self
Taking a ritual bath of purification, or maybe fasting for a day before ritual, smudge purification (purifying yourself with incense). Anything that purifies yourself. This also should include grounding and centering to balance yourself before ritual.
Purification of ritual space
Physically cleaning it (if indoors the space is usually vacuumed, outside sticks are removed, or used in ritual, and the area is generaly cleared of anything you might step on -like rocks-); then after physcially cleaning it, you take the ritual broom, or it is sometimes called a “besom,” and clean away the astral garbage and psychic clutter that builds up in the area.
Casting the Circle
Everyone has a different method for this it seems. Basically the boundary is set with cords, it is sealed with the water, salt, incense, and candle (not necessarily in this order, everyone has a different way to do it), the quarters are called (some use the gaurdians of the watchtowers, I use the elements), and then the Goddess and God are called (sometimes they are called first). The circle is there to protect the practitioner from harm. When you do these kinds of Workings it is like setting a flare off into the astral realm, everything hears it and sees it, the circle is there to protect, and let energy out when sent, but keeps everything on the inside protected from the outside.
This can be a celebration of the Sabbat, meditation, spell work, celebration of an Esbat, or a ritual of thanks to the practitioner’s Patron deities, or anything else the practitioner wants to do. Energy is sent towards goal, simple feast follows. (the simple feast puts you back into balance when the energy is sent. Energy sent can mean for a spell, for thanks, healing, etc)
Closing the Circle
Goddess and God are thanked for presence, as are elements/gaurdians, and circle is sucked back up with the athame (ritual knife, not used for cutting anything).
That is what we generally do in ritual. It can be simple or elaborate. It is also different with each person, depending on resources and preferences, and also where they learned how to do it.