I’m going to run through the twelve signs, describing them more in terms of their Sun sign rather than any of the planets.
A planet in a specific sign can be similar to the Sun in that sign, even though different issues are handled. But this varies. Saturn’s description is probably the most different, which makes sense in that the rulership of both Sun and Moon is where Saturn is in detriment (opposite of rulership). As far as other planets, rather than what you read below, compatibility may or may not be more likely to correspond to the trines (four signs away) or sextiles (two signs away).
There is one source, The Secret Language of Relationships, that divides the zodiac into 48 parts. This was a revolutionary addition to astrological knowledge, and it happened in 1997. So you’d note that Sagittarius II is different in many ways than Sagittarius III, and Taurus I is different in many ways than Taurus II. But there is a core set of similarities between all Taureans and all Sagittarians.
Courage might be considered the hallmark of the Aries — and if you are an Aries, you’re often very direct, dynamic, pioneering, energetic and open. An Aries seems to need to do, often impulsively but still successfully. You’re more likely to be proficient in leadership. Aries is a Cardinal Fire sign and is known as the “ram,” and Aries has to do with the self, the ego, self-definition.
Ruled by Mars, you’d tend to be compatible (in this order) with Leo, Libra, Sagittarius, but often Taurus as well — at least, with the Sun sign. (Leo and Sagittarius, being both fire signs, are trine signs — 4 signs away, or 1/3 of the circle. Trines are, at least on a basic level, usually compatible no matter the planet).
Aries rules the head and face.
If you are a Taurus, the magic word is “reliable,” and being an fixed earth sign, you’re usually fixed, and down to earth! Taurus, and the second house, generally has to do with the material side of things, the physical, and values. Taurus is also known as “the bull,” steady, resourceful. You can be warm and loving and keen observers as a basic part of their personality, but, like the Aries, headstrong and stubborn — only in terms of inaction, rather than action. Taurus is ruled by Venus.
You tend to value security and stability, and unlike the Aries, are usually not spontaneous. You can be compatible with numerous signs, the most obvious being the earth signs (Taurus, Virgo, Capricorn) but also the water signs (Cancer, Scorpio and Pisces).
Taurus rules the neck and throat.
Gemini is the first “air” sign in the zodiac (mutable air). Air signs tend to be about the mental sign of life. If you are a Gemini, you’re very ‘mental’, are VERY communicative and also very adaptable and responsive — in fact, you will welcome change, value freedom, and love adventure, including travel. You may also be afflicted by nervousness. Mercury rules Gemini, and indeed, you as a Gemini are “mercurial”! If someone’s looking for a response to something, you’re first to give it.
You are often most compatible with air signs Gemini, Libra and Aquarius, but also share some compatibility with Leo, Virgo, Sagittarius and Pisces. Gemini is known as the “twins” and in many cases the Gemini has two, or more, facets to their personality.
Gemini rules the shoulders, hands and arms.
Cancer, known as the “crab,” is overall the most loyal sign in the zodiac and is a water sign. If you are a Cancer, you’re emotional, dreamy, and usually protective, patient, giving and nurturing. Cancer corresponds to the 4th house of the chart, and is about home and nesting. Cancer is ruled by the Moon, the planet of the feeling and emotional nature.
Empathy is the most important qualification for you as you value such a bond with another person above most other considerations. You usually do well with other water signs (Cancer, Scorpio and Pisces), earth signs (Taurus, Virgo, Capricorn), and perhaps Leo and Libra as well.
Cancer rules the breasts and stomach.
Leo is the “lion” and if you are a Leo, you may take on the mythic qualities of the Lion — strength, dominance, leadership, and just plain regal-ness — along with creativity, generosity, integrity, and the willingness to love without constraints.
Leo is a fixed fire sign and is ruled by the Sun. The fire is well under control with you, lending itself to a power and formative energy that makes quite an influence. Leo is usually compatible with all the fire signs (Aries, Leo, and Sagittarius), along with Cancer, Virgo, and Aquarius.
Leo rules the heart and back.
Virgo’s mantra is “I serve” and is also known as “the virgin” perhaps because, if you’re a Virgo, you’re among the most moral people in the zodiac and are believers in service. Serious, very selective, an analyst, problem solver and a good planner, you may be considered conservative on a personal level and often are dominant in personal relationships (though not often in the rest of life, given your propensity for service). You may take things literally and are some of the most conscientious people in the zodiac.
Virgo is ruled by Mercury, and thus has to do with communication and the mental side, but the flighty, mercurial nature of Gemini is firmly grounded in Virgo. Virgo is a mutable earth sign. You’re usually most compatible with Cancer, Leo, other Virgos, Scorpio, Pisces, and even Sagittarius (with a few caveats).
Virgo rules the abdomen and organs within (intestines, pancreas, and spleen).
Libras are the charmers and romantics — and if you’re a Libra, you’re more a lover than a fighter. Libra is symbolized by “the scales” as they usually believe strongly in justice, harmony and balance. To love and be loved is one of your prime goals, and beauty — in the environment, in the individual yourself — is a way to get there.
In the workplace you often excel when in the public eye. Libra is a cardinal air sign, and you’re usually most compatible with Aries, Gemini, and Cancer, and to a lesser extent Leo, Sagittarius and the other air signs. Libra is ruled by Venus.
Libra rules the lower back, kidneys, and ovaries.
The most intense and idealistic of all the signs, not just the water signs; if you’re a Scorpio, you want to get to the bare essence of things. Knowing that you’re sultry, magnetic, deep, exciting, and knowing that Scorpio is ruled by Mars and Pluto, it is not a stretch to understand that Scorpio has to do issues about sex and death.
Scorpio is “the scorpion.” You are usually most compatible with Cancer and Pisces, the other water signs (Scorpio is a fixed water sign), Virgo, and to a lesser degree Taurus and Capricorn.
Scorpio rules the genitals, blood, and bladder.
Knowing that Sagittarius is the “archer” and knowing that Sagittarius’ arrow is thought to “shoot for the truth,” you are the philosophical ones just as you are the most adventurous sign in the zodiac. You love travel, including to foreign countries and can find success abroad. You are fun, and are not judging — at least, not in the informal sense as you have the intellect to become judges.
Honest, sincere and ethical, you are often disappointed by fellow humans’ inability to fulfill their ideals and are, as a result, often interested in nature as something more pure. Sagittarius is a mutable fire sign, ruled by Jupiter and you’re usually most compatible with Leo and Virgo, and to a lesser extent, the other fire signs (Aries and Sagittarius), Geminis and Libras.
Sagittarius rules the hips and thighs.
Unlike the expansive nature of Sagittarius, who is ruled by Jupiter, Saturn rules Capricorn and since Saturn is the planet of restriction, paying your dues, difficulties, and one’s “shadow,” you are usually the most sober people of the zodiac (again, very unlike Sagittarians). You will work your way to the top in a very conventional way, and with determination few others have. You can be personally conservative like Virgos, and stubborn like Taurians.
Capricorn is “the goat,” a cardinal earth sign, and is most compatible with the earth signs and the water signs. Capricorn rules the skeletal system and knees.
Aquarius is also ruled by Saturn, and if you’re an Aquarius, there’s some sobriety to you nature, but you’re also ruled by Uranus, the most revolutionary and disruptive sign. You’re generally up-to-date on things, a believer in the scientific method (to the point that you may be hostile toward astrology), and usually friendly, but you also can be unpredictable and detached. Eccentricity and unconventionality are also things you’re likely to have.
Aquarius is known as “the water bearer” but is actually an air sign (fixed air). You are most compatible with the air signs (Gemini, Libra, Aquarius), and Leo.
Aquarius rules the lower legs and ankles.
The most compassionate and sensitive people in the zodiac either have sun in Pisces or another crucial planet (perhaps the Moon) in Pisces. Pisces is “the fish,” a mutable water sign, and since it is the last sign in the zodiac, it often corresponds to the end of life and merging with the Universe, to begin again — if reincarnation is a thing you believe in. If you’re a Pisces, your personality can be quite cosmic, and dreamy (which goes both ways).
You are most compatible with the other water signs (Cancer, Scorpio) as well as Virgo. You’re somewhat compatible with Taurus, Capricorn, and Pisces.
Pisces rules the feet.