Not to be confused with the Greater and Lesser Banishing and Invoking Rites of the Pentagram that are used in Solomonic magicks and in some Wiccan Traditions, the Pentagrams to which I refer in this post are simply drawn in the air, usually with a wand, as part of the "Erecting the Temple" Rite in Wiccan rituals.
Most Wiccan Traditions have some form of "calling the quarters" in their "Erecting the Temple" rites, and while it is sometimes "necessary" in some Trads to draw these pentagrams, in my Trad it is considered optional. However, whether or not you think it's a necessary part of your practice, it's good to know what the heck the books and live priests and priestesses are referring to when they say "elemental invoking and banishing pentagrams."
When the quarters are called and dismissed in erecting and "dropping" the circle in Wiccan rituals, five-pointed stars are sometimes drawn in the air, usually with the wand. The way that the star is drawn determines which Elementals it calls or dismisses. The reason that these pentagrams are drawn when calling or dismissing Elementals is that this act depicts the Elemental in relationship with the others as They exist as building blocks of our collective reality.
Another time at which these pentagrams might be drawn during the Erecting the Temple rite is when water is purified, salt is purified or blessed (depending on your Trad), and incense is lit. For instance, in my Trad, it is common to draw the "water banishing" pentacle in the water bowl to exorcise all impurities from the water and then the water is blessed using the "water invoking" pentagram. Same for the salt and the incense, but with "earth banishing and earth invoking" and "air banishing and air invoking" pentagrams.
Confused yet? I don't blame you if you are. But if you're not, or if you are studying Wicca with a qualified teacher or through books, you can find these pentagrams referenced liberally. Here they are: