As another poster, Tj --- mentioned, it is more involved than just "which sign can effectively be with which sign". It was a mistake for this to have become so watered down, for there to be daily Horoscopes based upon a Sun sign or one having traits only related to their Sun sign. No wonder some find it silly.
If a person actually wanted to consider Astrology, it has to do with more, having a natal
chart done showing "planetary placements" during one's birth date, time and place. Then, there are mathematical equations or measurements in creating a chart.
(I did not create this, so don't shoot the messenger).
There are 12 signs with an Element to each - being of either
Earth, Air, Fire or Water.
Aries, Sagittarius, Leo - Fire
Taurus, Virgo, Capricorn - Earth
Libra, Gemini, Acquarius - Air
Pisces, Cancer, Scorpio - Water
Then, the signs are classified as Cardinal, Fixed or Mutable - being Positive or Negative = Masculine or Feminine.
The
HOUSES are where one's planetary (Planet) placements "will land", such as Love & Romance, Finance, Friendship, Career, Self, Homelife, Communications, and more (so one has more than
one sign influencing their personality, sometimes several of one sign, in one chart. You might have many planet placements in Leo, some Pisces, some in Cancer, Capricorn - so you would have a lot of Fire, a bit of Water, and a bit of Earth - with no Air. Or, you could have a fiery Sun sign, but not have much else fiery in your chart overall (personality), which means you may have more characteristics of different signs. And yes, there are positive and negative traits connected to each sign, just as we know everyone possesses anyway, to some degree.
Then, as mentioned, a
MOON placement means a bunch, because it is all about emotions, so it has a lot to do with anyone's personality.
Mars and
Venus placements for instance, denote one's love and romantic leanings.
Are you still with me?
There is more and is involved - doubtful many would ever consider creating a chart for both parties before settling in with another or even having sex. But, probably not good to say "Hey, you are a Leo and I am an Aries, so we are supposed to get along". If
anything, find out what one's Venus and Mars placements are before becoming involved or having sex. Also, find out one's moon placement.
There is an old book, "Star Signs for Lovers", in which the author has already configured, based only upon birthdates to correspond with yearly tables, that indicate where
Mars and Venus were at birth, defining the character, motivation, leanings of a person in regards to
love and sex - also in a rating of A, B, C, D. (I would refer to it when dating, but would ignore what the findings were due to liking a guy, but learned there was something to it and stopped ignoring it). I began looking up Celebrities by birthdate, which is interesting, surprising, (sometimes guessing ahead by personality what categories they might land. You should see what it says about Cosby's profile
).
The book is out of print, but a used copy may be available. (The book's birth years only go up to 1965 I think, but all you would need to do is find out what a person's birthdate is and look up their "Mars & Venus" placement in an online chart", then you could still look up "Mars in Cancer, Venus in Scorpio" (or whatever their's is) in that book. (An Online site that gives a profile, may not give the same sorts of insights as this book will).
Hey, I just retained this stuff from having read up on it years ago, but never calculated a chart, as an actual Astrologer could do. (I have correctly guessed a person's Sun sign if around them a while, though as said, there is more to it than just that and can tell what else may be in a person's chart). I don't live by it, but consider, due to some confirmation involved.
So, should we get started on Numerology?