Casting a Sacred Circle
In Wicca, casting a circle of sacred space is an integral step to any ritual or spell work.
As the circle is cast, it joins our realm with the Magickal Realms, and as such, it acts as protection from destructive or malignant forces. It's also part of preparing you for your ritial by putting you in the right set of mind.
Most Wiccans place a small alter at the center of the circle, facing North, with all of the tools they will need:
Athame or sword, broom, representation of the God and Goddess, candles (usually Gold for the God and White for the Goddess along with a candle of the appropriate color to match your spell or ritual purpose). Representations of the God and Goddess and their candle are placed with the God on the Right (projecting) and the Goddess on the left (receptive).You may also include white sage for smudging (additional spiritual cleansing). Once the circle is cast, do not leave/break the circle until the rite is complete!
Cleanse your ritual space where you will cast your circle. Start by tidying up, a clean, clear area helps you to give proper respect to the space and, once again, helps to mentally prepare you for Magickal workings.
By now, you're starting to shift to a meditative state, helping to channel your spiritual power and influence. To cleanse the area spiritually, the most common practice is to use a broom, sweeping clockwise around the perimeter of the circle, this pushes an negative energy away from the circle and attendees. You may also have another person follow you with the smoking white sage.
Note: Many Wiccan traditions use an archaic Irish/Scottosh Gaelic word for clockwise, 'deasil' (pr. jeshel), litterally, 'the way of the sun'. Alternate spellings are often used. The spelling doesn't matter much.
Place a candle at each of the cardinal points, North (Earth), East (Air) , South (fire) and West (water).
The final casting of the circle can include a variety of objects, but most often simply an athame, wand or sword. Walking deasil around circle with the casting object in your right hand (projecting) pointing to the the boundary of the circle, sending your energy into the Earth and visualizing creating a protective bubble or sphere above and below the circle. You may also speak an invocation, stating your intent. These can vary greatly, the most important thing is your INTENT, not the actualy words. A short example would be something like, "I cast this circle as sacred space and protection from negativity, in honor of the God and Goddess, so mote it be". Walk around the circle 3 times, repeating your invocation with each pass.
Now it's time to invite the protection of the elements. Light the candles at the cardinal points, usually starting with North and working deasil around the circle. Before lighting the candle, invoke/invite the spirits of the elements to attend and guard your sacred space.
Some traditions are quite formal with long and specific invocations, some are informal and short, some even do so silently. Light the candle as you finish the invocation.
Finally, humbly invoke the God and Goddess to attend and bless your ritual or spell work, lighting thier candles are you complete the invocations.
Most traditions finish invocation of the elements and deities with "Hail! And Welcome!"
Now you're preperation is complete. By now, your conciousness has shifted to a sacred and spiritual state. Some time in silent meditation can help further your shift to this powerful mental and spiritual condition.
Enact the spell or ritual to completion.
Bid farewell to the deities, then the elements, thanking them all for their aid, protection and blessings, snuffing the candles as you go.
Banish/release/open the circle in a similar manner in which you cast it. Some traditions reverse the direction, counter clockwise, referred to as 'widdershins', from an archaic Germanic word meaning 'against the way' or against the Sun'. Some Traditions do everything deosil, believing that widdershins is only for negative workings.
That's it, the rite is done. A celebration and some shared time with the attendees after the ritual helps bring everyone's comciousness back to 'this realm', a return to normalcy.
Disclaimer: This is not meant to suggest that this is the only way to cast a circle, it is only suggestions and examples. In my opinion, there are many ways of doing things, there is no exact 'right way'. The most important aspect of any worship, ritual or spell is intent. If you disagree, that's fine.