The first thing is to start with the form of the hand.

In our approach we choose a classification, which reflects the 4 elemental categories Earth, Air, Fire and Water. The elemental type is defined by the shape of the palm in relation to the length of the fingers.

Earth Hand = Square palm + short fingers
Air Hand = Square palm + long fingers
Fire Hand = Oblong palm + short fingers
Water Hand = Oblong palm + long fingers

Earth Hand
The Earth hand is square and solid. The fingers are short and the palm exhibits few lines. Those that do appear are strong and well defined. Subjects with Earth hands tend to be level-headed, no-nonsense people. Physical experience may be more important than intellectual pursuits. Practical in nature, the Earth type may be conservative and probably prefers spending time outdoors. It has been my experience that the Earth type is the least likely to seek out a palmist for a reading.
Astrologically, the Earth signs are Taurus, Virgo and Capricorn, but this doesn’t always fit.

Air Hand
The Air hand has long fingers and tends to have an abundance of clear lines in the palm. Air types spend their time in the intellecual realms. They are curious and full of ideas. They thrive on nervous energy and may be prone to worry and stress. Air types are communicators and are often good at working with the public. However they may tend to intellectualize their feelings and can have difficulty with close, personal relationships. Astrologically, the Air signs are Gemini, Libra and Aquarius.

Fire Hand
A hand with an elongated palm and short fingers fits into the Fire classification. The lines in the palm are usually strong and well-defined and the hand may have a busy or vibrant feel to it. Fire types are energetic and action oriented. They have a need for variety and may lack patience. Then tend to be individualistic and often make good leaders.
Astrologically the Fire signs are Aries, Leo and Sagittarius.

Water Hand
Water hands have many fine, spidery lines and both the palm and the fingers are long. The Water hand is found on the sensitive, emotional type of individual. Water types are caring, receptive and artistic. They are primarily motivated by feelings. They may have trouble coping with stress and are often happiest in a peaceful environment.
Water signs are Cancer, Scorpio and Pisces

The next step is to read the lines in the hand
The lines in the hand can be divided into 3 groups: the major lines, the minor lines and the personal lines. There are 3 major lines to be found in the hand. These are the Life Line, the Heart Line and the Head Line. The minor lines run vertically in the hand and each is named for the finger under which it terminates. Everything else is considered a personal line. The personal lines may have names and fit into categories though there may be some lines that are quite unique to the individual. It is through practice and experience that the palmist can learn how to interpret these lines.
Though most hands will have the 3 majors and at least one or two of the minors, every hand is unique and many of these lines will be absent from a number of the hands you observe.
The lines in the hand change all during the life and reflect the changes in behavior, attitude, lifestyle and experience of the individual. Taking dated prints of the hands provides a record of what the hands reveal at a particular point in time.
The Major Lines
The Life Line - The Life Line begins at the edge of the hand between the thumb and forefinger and arcs downward around the thumb area. Contrary to popular belief, this line does not indicate length of life. It does identify vitality, robustness or weakness, enthusiasm for living and state of health.
The Head Line - The head line begins at or near the beginning of the Life Line and moves horizontally across the hand. It represents mental capacity and the intellectual style. The length of the line indicates amount of time spent in the realm of thoughts. A curvy Head Line is a sign of an intuitive thinker while the very straight line indicates a logical disposition.
The Heart Line - The Heart Line begins under the little finger (Mercury) and moves across the upper palm. The Heart Line reveals the style of relating, the degree of sensitivity of an individual and the emotional history. If the Heart Line sits low in the hand, it is an indication that the heart rules the head. If the line is very straight it shows a person who intellectualizes the emotions.
The Simian Line - Some hands have only 1 line moving horizontally across the upper hand, a combination of the usual 2 lines representing head and heart. This marking is known as the Simian Line. With the Head and Heart lines running together, the emotional and mental functions do not operate separately. Those who possess this line exhibit intensity of temperament.

The Minor Lines
The Line of Saturn - The Saturn Line begins just above the wrist and moves up the hand to the middle finger. It is commonly known as the Fate Line. This line represents the measure of personal success and the subject's attitude toward handling responsibility.
The Line of Apollo - This line is also known as the Line of the Sun. It appears under the finger of Apollo, the ring finger. The presence of the Line of Apollo indicates artistic talent. This line is often short, rising just above the Heart Line and may not appear on the hand at all.
The Line of Mercury - The Line of Mercury may sometimes be referred to as the Line of Health or the Line of Inner Dialogue. It may not appear on the hand but when it does it rises from the base of the hand and angles up to the Mound of Mercury under the little finger. When present this line will give information about the subject's nervous system. It is also an indication that the individual is seeking a path of self-improvement or spiritual growth.