“Hey, I have a Mars in Gemini. What does that mean in my chart?”
“How does Mercury in Virgo in my second house affect me?”
“Is my Capricorn Moon a bad thing?”
I don’t know. Really. I don’t have enough information to tell. I am a proponent of looking as a birth chart as a whole (as most astrologers are). Sure, it can be a fun parlor trick to whip out a trait or two based on an isolated component of the chart, and have someone go “Oh, that is so me!” but people are more than just a collection of behavioral traits and ticks. And if you look at each piece separately, it can give a wildly divergent and contradictory picture of a person. “Oh look. This person is a Taurus so they are slow and steady, but they have a Mars in Aries so they move and act fast.” Well… no… not exactly. The best way to examine a birth chart is to look at it as a gestalt: a set of elements considered as a whole and regarded as amounting to more than the sum of its parts. After all, people are more than the sum of their parts.
A Mars in Aries will not make someone with a Capricorn Sun suddenly bold and rash, unless perhaps that Mars is conjunct Jupiter in the first house. And even then, he will be bold for a Capricorn, and Capricorn almost always thinks and plans before acting. Put that same Mars/Jupiter conjunction in the chart of a Sagittarian Sun, and step aside. Here comes the runaway freight train. Unless… what if that Sag has Saturn conjunct the Sun? Or Saturn conjunct the Ascendant?
Asking an astrologer’s interpretation about one component in your chart is like asking a chef if garlic is good to use when cooking. It depends upon the recipe. It’s great in tomato sauce, not so hot when you’re baking a cake.
When I start examining a chart, I assess the Sun, Moon and Rising Sign first. That’s the core. What signs are they in? What aspects do they make to other planets? What houses are they in? Get a handle on that information and you have a handle on, perhaps, 66% of a person’s chart. And once that is understood, the rest of the information in a chart is nuance and degrees of tone. A Taurus Sun conjunct Saturn, with a Capricorn Moon and Virgo Rising will rarely be bold and rash, even with Mars & Jupiter conjunct in Aries in the first house. And a Gemini Sun conjunct Jupiter, with a Leo Moon and Aries Rising will most likely not be mellow and quiet even with Mercury & Venus in Taurus. There’s a big picture here, and we have yet to add in the effects of Pluto, Neptune and Uranus yet. But that big picture, when properly drawn, is a complete human being, finely etched in detail.