The astrological signs come in four flavours (Fire, Air, Water, Earth, also known as the Quadruplicities) and three characters (Cardinal, Fixed, Mutable aka the Triplicities). Okay, so what does that mean?
Let’s take the flavours first. Any given party is very likely to have a mix of the various signs so we’ll use that as an analogy. So, Fire signs (Aries, Leo, Sagittarius) are generally outgoing, extrovert, generous, cheerful and possibly a bit loud. There’s a tendency towards tactlessness but they are usually fortunate enough to get themselves out of all but the most horrific of messes.
Air signs (Gemini, Libra, Aquarius) are chatterboxes, social butterflies (maybe not so much with Aquarians), intellectual and possibly untidy. They can give the feeling that one is the only person in a whole roomful of people, right up to the point where they move on to the next and one is left feeling ever-so-slightly bereft…
Water signs (Cancer, Scorpio, Pisces) are the feelers of the zodiac. If you see someone tearing up at the mere suggestion of something sad—or happy, for that matter—chances are that there’s Water in that person’s chart and quite probably near the surface—Sun, Moon or Ascendant.
Earth signs (Taurus, Virgo, Capricorn) are mainly practical types. They will quietly beaver away at whatever it is they do and get the job done. At our hypothetical party they will be the ones who take their empty glass back to the kitchen for a refill, rather than just parking it in a place convenient for getting knocked over (smashing optional) and will gather up what they can see and/or carry on the way. They tend to be a bit earnest (Virgo, I’m looking at you) and appear to be rather slow.
The characters (Quadruplicities) can be looked at by using an analogy of the four seasons. Cardinal signs kick things off, get them started, give the initial push; think March (Spring, Aries) June (Summer, Cancer) September (Autumn/Fall, Libra) and December (Winter, Capricorn). Fixed signs take that push and maintain whatever has been started; April, Taurus; July, Leo; October, Scorpio; January, Aquarius. Mutable signs are responsible for winding up the old impetus/season, making it all nice and tidy in preparation for the next one; May, Gemini; August, Virgo; November, Sagittarius; February, Pisces.