A good place to start in an astrological relationship analysis is by first judging the elemental and modality balance in the natal chart. Often at a time of crisis in a partnership, it is useful to observe how each person reacts according to their horoscope and element balance. Ordinarily, there are many factors we can observe when assessing the style or temperament of a couple, but to keep it simple, the balance of the two charts is a good place to begin in any study on the nature of a relationship.
If one partner has an abundance of planets in the FIRE signs (Aries, Leo, Sagittarius), they are usually warm, have plenty of energy, enthusiasm, and vitality. They are unparalleled optimists, and to them, life is one big adventure.
A predominance of planets in the EARTH signs (Taurus, Virgo, Capricorn) shows a steady, practical individual and one who is far more cautious than their fiery counterparts and is less inclined to take risks. Therefore we see two fundamental differences in the relationship between FIRE and EARTH individuals.
Earth type people are often accused of being pessimistic due to their negative, introverted and grounded nature, but they have dogged persistence, and in times of crisis they can be relied upon to find a reliable solution. These people are more inclined to worry about paying the bills than the next big adventure (Fire).
A person with an abundance of planets in the AIR signs (Gemini, Libra, Aquarius) is more interested in the realm of ideas, communication, and the intellect. Air signs are logical, rational and objective and are prone to analyzing difficult situations. These people bring clarity, objectivity and a new perspective into any relationship and will bring these same innate qualities to the union when they hit troubled waters.
The WATER signs (Cancer, Scorpio, Pisces) are also considered to be negative and introverted. A person with plenty of planets in water is said to have a strong psychic sensitivity, compassion and understanding. Water people feel the undercurrents of any situation and tend to feel their way around life. They may be experienced as the overly emotional types in a relationship, responding with feeling to a crisis in the partnership.
CARDINAL signs ( Aries, Cancer, Libra, and Capricorn) are ambitious and need to take action, the urge to achieve and succeed is important.
The FIXED signs (Taurus, Leo, Scorpio, and Aquarius) are the most inflexible signs and are often resistant to change, so you may realize why they are not as enthusiastic about sudden changes happening in the relationship.
MUTABLE (Gemini, Virgo, Sagittarius, and Pisces) signs are extremely adaptable, but they do have a tendency to scatter their energies, have difficulty staying focused, and they prefer intellectual pursuits.
House placements are also important and they often compensate for missing elements or qualities.