Check the planet that rules your rising sign. Mine is Gemini, so I find Mercury. In my Whole Sign Chart (I see no reason to complicate matters with theoretical 'houses') Mercury lives in the 12th house in the sign of Taurus. For me, Mercury in Taurus in the 12th house rules my chart. He is my Prime Influencer. My Ruling element is Earth (Taurus), not air (Gemini). Even though Gemini is air and is my Rising Sign, Earth Rules in my life Energy. Got it?
Throughout my life when people asked my sun sign and I replied "Gemini", they almost always replied back to me, "Gee, you don't seem like a Gemini!" And yes, I do love to share my ideas verbally with some level of excitement, but I am also sensual and devoted like a Taurus. And my life is like a hobby or a side business, like the 12th house. No matter how hard I try, I can't get past those issues, so I have figured out how to enhance them instead of make them go away (because we cannot).
Of course there is more to a chart, but 'just a sun sign' is not good enough for people who want real insight. When a Pisces Sun is conjunct Saturn, that person will be a lot more solid than a traditional Pisces 'cookbook' description. Then people will say to her "Gee you don't seem like a Pisces." And then people will say, "Well, what did I tell you about astrology being bullhonky?" And you are left with no real answer, because you have not dived deep enough to explain all the details. And then, guess what? You can't explain anything to a person who hasn't learned the most basic tenets of a discipline! Yes, it can be disconcerting, but take heart. Keep digging, continue noticing. This is how one learns astrology.
And for those who say it is not 'science' because... ("Anecdotal evidence doesn't equal a statistical significance.") ... No one person is a statistic. No one conforms to any one rule. That is why Astrology and Life are a bit complicated. We continuously adjust our place within the context of our present situations.
The truth is, science changes its premises all the time for many good reasons; for instance, different researchers have slightly different approaches, and, like astrologers, they seldom agree or they often compete. For the past fifty years science research has been primarily funded by the Corporations that have a vested interest in the products they research. Follow the money.
If your rising is Aries or Scorpio, look to Mars' sign and house
If your rising is Taurus or Libra, look to Venus' sign and house
If your rising is Gemini or Virgo, look to Mercury's sign and house
If your rising is Cancer, look to the Moon's sign and house
If your rising is Leo, Look to the Sun's sign and house
If your rising is Sagittarius, look to Jupiter's sign and house
If your rising is Capricorn, look to Saturn's sign and house
If your rising is Aquarius, look to Uranus, or Saturn's sign and house
If your rising is Pisces, look to Neptune, or Jupiter's sign and house
The next step after you find your ruling element and house, discover your Mars sign, house and aspects. Mars is you, demonstrating your power; Mar's fire determines how you operate your life; how you maneuver through tasks and challenges. Mars is the fire within. We are compelled to do our fire energy. Mine is in Virgo in the fourth house. So my Prime Mover is Housekeeping. Yes, really. I am a Natural Born Homemaker. Whoopee! Ever since I was a girl, I have always felt most alive at home. Even after a long exhausting day of errands, the minute my foot steps over the threshold of my home, my energy expands and I feel better. I may sit and rest a bit, but not for long, because all the 'to do's' of the house will call me to my feet.
What is the condition of your Mars? This is so important that I do an entire reading around this one Planet.
(An interesting sidebar on the word 'maneuver' ... it is from the Latin 'mano' or 'hand') Mars is your 'to be' energy and as such s/he is your 'push' through life, or how you 'handle yourself.' You will know when you are 'Doing your Mars' because that is when you feel the most fulfilled.