The Golden Dawn popularised the Lesser Ritual of the Pentagram in the late 19th century, making it one of the most foundational elements of modern western magick. The original ritual came in two varieties, a 'banishing' ritual and an 'invoking' ritual. The only actual difference between the two is in the way the pentagrams are traced in the air, the words and structure remain the same.
It seems like most occult writers have fixated on the banishing ritual, usually advocating both its use as an opening for other rituals, and as a daily practise. The justification is that it is supposed to clear the air (metaphorically) of negative, or merely 'mundane', emotions, thus putting you in a spiritual, magickal frame of mind.
This does make sense. However, there are a few issues involved that I seem to have trouble getting my brain around, which have led me to think that thinking of such rituals in terms of 'banishing' and 'invoking' is restrictive and not necessarily the best way to go about things.
There is the question of what actually makes a ritual 'banishing' in the first place. A mere arbitrary difference in gestures doesn't seem to quite cut it for me. The meat, if you will, of the ritual is the words of power and names of deities, angels or whatever, uttered. And such names, by their very nature, are invoking in and of themselves. When designing my own pentagram rituals (one should preferably design one's own, and make it truly personal), I have often had great difficulty in distinguishing between banishing and invoking forms.
There is also the question of whether banishing everything willy nilly is even desirable. It is the world surrounding us that defines us. Both negative and mundane feelings are part of us, after all. No magick could happen without the help of the mundane world, and to shut it out entirely, even in ritual, seems counter-intuitive.
It could perhaps be more convenient to think of the Ritual of the Pentagram as 'balancing', rather than 'banishing' or 'invoking'. The aim would be a harmony of the inner and outer universes, an awareness of both universes, in equal measure.
The ritual often combines the four elements and/or other symbols that signify the totality of the universe. When everything is one, there should be no need for banishing. The negative and the mundane remain, but take their rightful place as part of a greater pattern, and (hopefully) become less overbearing in the process.
This concept of balancing could perhaps be seen as leaning towards invoking, and in fact the method of uniting the universe is through invoking the different components of the whole. But thinking in such terms would be beside the point, and whether you call it 'balancing' or 'invoking' doesn't really matter. The dichotomy of banishing and invoking ceases to exist, there is only the one ritual. (If different forms of symbols, such as the pentagram, exist, the invoking form may be the more appropriate. But in the end, the choice is more or less arbitrary.)
Of course there may be times when one desires to banish some specific negative emotion, entity or whatnot. But there are probably better ways of going about this than the Ritual of the Pentagram.