I have used the Lesser Banishing Ritual for many years. It was created by the Golden Dawn in the 1800's and has been picked up by modern occult groups of all religious flavor since then. It's obvious Judeo-Christian symbolism and invocations are a great addition to Powwow should you wish to add a more ceremonial element to what you are doing.
I use the Lesser Banishing Ritual (LBR) as a way to center myself or call on protection or cleanse an area of energies. It has all sorts of uses and benefits, and is really simple to learn and do.
You should know that there are many variations on the LBR. There are also some variations that add more parts. You can find these by doing a quick internet search. However, what follows is the variation that I personally prefer to use. I've included the translations of each intonation to the best of my ability.
To begin, you'll need an area where you will be alone and without distraction. I have a white robe that I sometimes wear when doing this, but mostly it's done in whatever I happen to be wearing at the time. If you have cerremonial ritual tools, such as a dagger, then you'll want to use this as well. But if not, you can just do it without tools and props. It's a matter of personal preference and convenience, so don't stress over it.
Face East. Take a few deep breaths. Visualize yourself growing larger than the room or space that you are in... larger than the town you are in... larger than the earth... Your feet are still firmly planted on the ground but your mind has expanded far beyond.
Touch your forehead with you dagger (or right hand) and intone AH-TAH which translates as "For thine is"
Touch your chest (point the dagger downward) and intone MAL-KOOTH which translates as "the Kingdom"
Touch your right shoulder and intone VAY-GAY-BOO-RAH which translates as "the Power"
Touch your left shoulder and intone VAY-GAY-DOO-LAH which translates as "and the Glory"
Clasp your hands upon your chest and intone LAY-OH-LAHM, AMEN which translates as "Forever, Amen"
Facing East, trace a banishing pentagram of blue flame in the air before you and intone YE-HO-WAY which is the unknowable name of God.
Thrust your hand or dagger into the center of the pentagram and trace a line to the South.
Facing South, trace a banishing pentagram of blue flame in the air before you and intone AH-DO-NIE which translates as "Lord"
Thrust your hand or dagger into the center of the pentagram and trace a line to the West.
Facing West, trace a banishing pentagram of blue flame in the air before you and intone EY-AYE-AH which translates as "I AM"
Thrust your hand or dagger into the center of the pentagram and trace a line to the North.
Facing North, trace a banishing pentagram of blue flame in the air before you and intone AH-GLAH which translates as "Thour art mighty and forever, My Lord".
Thrust your hand or dagger into the center of the pentagram and trace a line back to East.
Extend both of your arms out to each side.
Say "Before me RAH-PHY-ELL. Behind me GAH-BREE-ELL. On my right hand MEE-KAY-ELL. On my left hand AUR-EE-ELL. Around me flames the pentagrams, and above me shines the six-rayed star"
Visualize the pentagrams flaming around you and, above you, see a blue flamed hexagram.
Now give yourself a moment to see and feel and experience the ritual you have just done. When you feel ready, relax yourself and go about your business. The LBR effects will fade on their own.