I was involved, for a short time a while back, with a small group of magicians who were without a doubt... hardcore. I was invited to the home of one of the magicians for a day of marathon magick. I was told ahead of time to work on a quick, effective banishing technique.
We went into the basement. This was my first official meeting with the particular group I was working with. I was told, in a joking manner, "This is your first time at Fight Club, so you have to fight." It was explained that I was going to be involved in alot of ritual work, and that I had to be able to banish quickly, and well.
I'd always thought of banishing as a way to balance and center, get in the right mind, create a working space, etc. I was not really prepared for what was about to happen. I was told that a demon was going to be evoked into a triangle on the floor in front of me, and my job was to make it go away in a timely manner.
I stood against the wall, breathing deeply and mentally preparing myself, while two guys performed a goetic-like evocation ritual about 3 feet in front of me. When they were done they told me "ok, it's here." I saw nothing. I focused on the triangle and shouted a short incantation. A large banner flew off the wall on the other side of the room. Everybody kind of laughed, and said "It's still here". I repeated my performance, and began hearing ALOT of noise coming from outside... people yelling and stuff. "That's to distract you. Focus. Ignore it." I repeated my Banishing again, and again. After some time I thought to myself "I cant do this". One of the other guys said "Yes you can", as if he'd heard my thoughts. I gave it one more go, from the heart, and they said it was gone.
After we were done, and everyone else had vanquished their own demon, one using a technique "borrowed" from one of the Harry Potter movies... which cleared the room so well I almost ran away myself, I was told that it was the demon telling me I couldn't do it earlier. The other guys were much more experienced at this type of thing than me, and said they could hear it and see it, and that I would be able to as well, when my skills got better. I was also told that the evoked entity was an elemental designed to annoy me and distract me, and that it couldn't have harmed me in any way. One of the guys also told me that it, magick, all boiled down to energy manipulation, and that the better I got at focusing my energy the better I'd be at Banishing, and everything else I did magickally.
Since then I've experimented with various types of banishing techniques, for various types of situations. I've tried everything from a simple smudging before meditating to Fireclown's Chaos Ruby, the LBRP to Psionic shielding. I've become a firm believer in using different banishing's for differnt situations as well.
The point... when your backs up against a wall, you better be able to banish quick and effectively.
Simply stated, banishing means to send something away. In magick, it is used to clear a person, area, home, etc. of negative energy, spirits, whatever. I'm a huge believer in the idea that a banishing should fit the situation. For instance, if I'm going to perform a long ceremonial type thing I'd probably perform a more complex banishing ritual (something like the LBRP or the Star Ruby) than I would if I were just going to meditate, when I might only visualize or physically draw a circle, for example, around me, or simply smudge the area with incense.
I equate my different ideas about banishing loosely to Peter Carroll's five levels of magickal activity: sorcery, shamanic, ritual, astral, and high magick, which I consider open-handed magick, generally.
Sorcery-style banishings might include such things as witch bottles, protective charms, and various protection/evil warding fetishes of different cultures. A necklace, or ring, with a protective symbol on it may be an effective banishing, just as crosses ward off vampires. The "word spell" might also be considered a sorcery type banishing. Such phrases as "Apo Pantos Kakodaimonos" and "Este, este, Bebeloi" would be good examples of a word spell telling "little nasties" to depart.
Smudging is something I consider to be a shamanic-type banishing, mostly because of movies and television's portrayal of the herb burning medicine man. I'd also consider any of the various types of "cleansing" rituals involving water, fire, incense, salt, and whatnot to be of this type. Admittedly, I don't know alot about shamanic practices, and I'm sure there are many more ideas that could be categorized here.
The Golden Dawn's Lesser Ritual of the Pentagram, Crowley's Star Ruby, Carroll's Gnostic Pentagram Ritual, and countless other Banishing Rituals fall into the area of Ritual Banishings. All of the one's just mentioned are good, as well as many others out there. Most banishing rituals serve several different functions, actually. First, most banishing rituals are designed to prepare the magician for further magickal work, whether it be meditation, astral travel, evocation, or whatever. They, in some way, generally get you ready to go. Second, they usually, in some way, create sacred space. This is typically done by casting a circle, or defining a "seperate area" in some way. Third, they clear the area of unwanted influences.
Astral Banishings can be simple or elaborate. They are performed astrally, or in your mind, and require no movement, physical tools, or anything of that nature. Most any ritual banishing can be used astrally, as well as many simpler techniques, such as simply visualizing yourself in a sphere, or standing in a flaming pentagram, or flinging astral saw blades at the unwanted influences, or any other techniqie you can visualize intensely.
In my opinion, working with all these various forms of banishing, over time, will lead to an open-handed, ongoing "Banishing" of unwanted influence around the magician. I've been asked which category Banishing with laughter, which is so common in modern chaos magick, falls into. I've used the technique, as I'm sure many people reading this have. I'd personally place it into the open-handed category.