The following technique is a very formal method of casting a circle.
 Do not feel obligated to follow it perfectly, for there is not one 
true correct way to fashion any spell or sacred space. Allow for 
change. Remember, whatever you feel comfortable with is the best way 
for you. Also note that this method is relating the elements to the 
directions as per the Southern Hemisphere, south coast of Australia, 
where I am situated. 


Hail, Guardians of the Watchtowers of the East,
Powers of Water.
I invoke thee and call thee
By the waters of Her living womb,
Be here now and Blessed Be!

Hail, Guardians of the Watchtowers of the South,
Powers of Air.
I invoke thee and call thee
By the air that is Her breath,
Be here now and Blessed Be!

Hail, Guardians of the Watchtowers of the West,
Powers of Earth.
I invoke thee and call thee
By the earth that is Her body,
Be here now and Blessed Be!

Hail, Guardians of the Watchtowers of the North,
Powers of Fire.
I invoke thee and call thee
By the fire that is Her spirit,
Be here now and Blessed Be! 


Walk around the circle deosil, or 'sunwise', or 'clockwise' (unless of
 course you prefer perform everything in the opposite direction to 
that that is done in the Northern Hemisphere, in which case you should
 also call the corners in opposite to that which I have stated) with 
your outstretched arm or athame(while doing this, you should visualise
 a blue-purple energy flowing out of the blade or your arm forming a 
real, tangible sphere, going not only around you and voer your head, 
but into the Earth as well), then say:


 The circle is cast, 
We are between the worlds. 
By the power of the Mother,
Let no unwanted spirits enter.


Most important is the strength of the visualisation. As you call to 
each of the directions, feel them with all of your senses.
East = Water, life-blood, fertility, flowing.
South = Air, wind blowing, breath that gives us life.  
West = Earth, Mother, strength, groundedness.
North = Fire, flames, sparks, desire.
When you have finished all works of magick or rituals, be sure to 
release each of the directions and open the circle. This is very 
important. In reverse order, say:


I give thanks to the Powers of the North,  
Powers of Fire.
Go if you must, stay if you will,
Hail and Farewell.
Blessed Be!

I give thanks to the Powers of the West,  
Powers of Earth.
Go if you must, stay if you will,
Hail and Farewell.
Blessed Be

I give thanks to the Powers of the South,  
Powers of Air.
Go if you must, stay if you will,
Hail and Farewell.
Blessed Be

I give thanks to the Powers of the East,  
Powers of Water.
Go if you must, stay if you will,
Hail and Farewell.
Blessed Be


Walk around the circle widdershins, or counterclockwise (or deosil if 
you wish to invert everything), drawing the circle with your out-
stretched arm or athame (literally pulling the circle's power 
back into you) and say:


The circle is now open.