Not long ago, I was meeting with an astrology client who had more questions about other people than she did about herself. A lovely woman, with a Virgo sun, she was perplexed by the actions of other family members, especially a younger Taurus grandchild. "I just want to know all about Taurus," she sighed. And so I was able to explain that both signs were under the element of earth, which can confer a practical side and a touch of materialism. And then (in an all-too-typical air sign way) I remembered my first book, The Astrological Elements, was coming out the following month.

"I have JUST the book for you!" I said. And since she's a Virgo (mindful of details) I have every faith that she'll remember to email me about getting a copy. If only all my clients were as reliable. But then—what fun would that be?

I decided to write The Astrological Elements after many years of thinking about the distinctions between signs of the same element, and how none of the books I'd read in a long educational odyssey of astrological inquiry really explored and analyzed those distinctions. My first thought was that I'd create a multi-book series, starting with the first element of the zodiac: fire. I thought a bright red cover and the title "The Fire Book" would have a wide appeal. Certainly I'd had plenty of Aries clients (also a few Leos and the occasional Sagittarius). But I'd also had many earth and water sign folks who loved the fire sign people in their lives but didn't entirely "get" them.

"Why don't they finish things?" they'd ask. Or, "How come they didn't call when they said they would?"

To be fair, those other elements needed the same amount of attention (as a Libra, I always need to make those scales balance somehow!). I had dealt with plenty of Aquarians who were convinced they were water signs (they're "the water carrier," remember?) or Scorpions who thought they were earth or fire signs (because scorpions live in the desert where it's as hot as blazes, you know?).

We all need a "how to" manual when dealing with other folks, and knowing their sign (thus their element) gives one an enormous advantage in a variety of milieu. Just to get you started: the fire signs are Aries, Leo, and Sagittarius—excitable and exciting, they can light up a room, or light a fire you can't put out! The earth signs are Taurus, Virgo, and Capricorn—and, as aforementioned, they are practical and methodical, materialistic and aesthetic. The air signs are Gemini, Libra, and Aquarius. They can be capricious and forward, dithering and directed. The water signs are Cancer, Scorpio, and Pisces, and are presumed to be emotional (they are), sensitive (very often), and perceptive.

If you're the same element as a friend, lover, family member, or co-worker, the prevailing wisdom says you'll share characteristics. Therefore a Gemini should be able to be compatible with a Libra or Aquarius. These signs can be verbally dexterous, philosophically flexible, and freedom-loving. Yet are they a good match? Well, says the thoughtful astrologer—a good match for what? Air signs in a relationship with one another will never run out of things about which to talk. However, decisions large and small may be a problem. Where to send the kids to school? Where to go on vacation or what to have for dinner? But what if there are problems? What if the two air signs constantly founder on the shoals of stasis?

And I've seen two earth signs together who literally put one another to sleep. Earth is one of those signs that needs stirring up—on their own, they'll continue with their routine. Earth sometimes needs a fire sign around to renew their sense of purpose. And fire signs can always use more stability! Fire signs as romantic partners can be passionate and combustible, and if they can survive one another's moods and tempers, this can be an enduring relationship. As for water signs, this pairing works if both people have sufficient experience with people of other dominant relationships. Water signs are subtle and sensitive, and often need a refuge away from the world's cares. That refuge can be another water sign, certainly.

What happens when you get in the laboratory of emotions? Interesting experiments! What happens when fire and air get together? (Any second-grader who's had a visit from their local firefighters can answer this one!). Yes, MORE fire! The fire eats up the air, and tends to extend itself.

In my experience, relationships between an air and fire person find that the air sign person often becomes subordinate to the powerful fire sign personality. This is not their fault, necessarily, but something of which to be mindful.

Fire and earth, however, can be an excellent combination with more possibilities for stability. Think of how you make porcelain: fine-grained clay heated for a length of time. If a fire and earth sign pair can endure difficulties, they'll be the stronger for it. But acknowledging those difficulties is key.

What about a water sign added to the fire? Do you get steam? Absolutely. But the kind of steam produced is very different depending on which one of those signs is doing the combining. Too much water is definitely going to overwhelm the fire sign, and you end up with damp embers instead of a jolly steam bath.

Earth signs might seem to reinforce one another's positive qualities (solvency, responsibility), but they can also shine a light on the less-helpful characteristics (procrastination, lack of initiative). Yet put an earth sign with a water sign and you have the classic ingredients for a lovely and lush garden (unless there's too much water, in which case there's a lot of emotion and drama, or too much earth, in which case the part where people have feelings gets slightly strangulated). Air and earth can also grow a garden. This relationship is definitely enhanced if each person has just a little bit of water in their chart (the final ingredient which helps you to talk about your feelings as well as perceive them!).

Finally, air and water. You can get the bubbles that go up your nose (in a delightful way) from a glass of champagne or the bubbles that come along with a too-rapid reemergence to the surface after scuba-diving (ouch!). Air and water together can be charming company for one another, as long as each understands the basic parameters of their own and their partner's personality. I've had plenty of consultations with water sign folks determined to make air sign partners "settle down," and air sign partners who can't understand why their water sign counterpart won't "lighten up."

Ultimately, all kinds of sun signs can combine with others, but having a sense of the emotional and intellectual apparatus you bring to your relationships—whether they're family, love-based or office-centered—can only make you a more successful and sensitive partner.