How to read a chart

The biggest beginner mistake is reading placements one at a time like a cookbook ("Moon in Gemini means…"). A real reading synthesises: it finds the few themes that repeat across the chart and tells them as one story. Astrologers call a theme that appears three times "confirmed", the rule of three.

What you need

Exact birth date, birth time (as precise as possible, ideally from a birth certificate) and birthplace. Free chart calculators: astro.com (Astrodienst), astro-seek.com, or apps like TimePassages. Without a birth time you can still read planets in signs and aspects, but not houses or angles.

The 10-step method

Overview (the shape). Is the chart day or night (sect)? Are planets clustered in one hemisphere or spread out? Any stellium? Count elements and modalities, what dominates, what's missing?
The Big Three. Sun (core identity, purpose), Moon (emotional needs, inner life), Ascendant (approach to life, body, persona). Describe each, then ask how they get along. Fire Sun + Water Moon + Earth Ascendant is a person with three very different languages inside.
The chart ruler. Find the ruler of the Ascendant sign. Its sign, house and aspects describe the direction of the whole life. This is the protagonist.
Angular planets. Any planet conjunct the ASC, MC, DSC or IC dominates the personality and life story.
Planets by house. For each planet: What (planet) + How (sign) + Where (house). Write one sentence each.
Dignity and condition. Which planets are strong (domicile, exaltation, angular, in sect)? Which are struggling (detriment, fall, combust, malefic contrary to sect)? Strong planets are tools; weak ones are growth areas.
Tight aspects. List aspects within ~3°. These are the chart's loudest dialogues. Note aspect patterns (T-square, grand trine, yod).
House rulers. For key life areas (career = 10th, relationships = 7th, money = 2nd, home = 4th), find the ruler of that house's cusp sign and where it lives. The ruler's house links the two areas.
Nodes, Chiron, Lilith, Lots. Add the karmic direction (nodes), the core wound (Chiron) and fortune (Lot of Fortune) as secondary layers.
Synthesis. Pick the 3–5 themes that keep repeating. Tell them as a story using the mythological layer: which gods dominate this chart, and what story are they telling?

Worked example (fictional chart)

Chart: Scorpio rising; Sun in Leo in the 10th; Moon in Pisces in the 5th; Mars (chart ruler) in Capricorn in the 3rd; Saturn in Taurus in the 7th, square the Sun; Pluto conjunct the Ascendant; Day chart (the Sun is above the horizon). Whole-sign houses.

Step by step:

Big Three: a proud, creative, sovereign identity (Leo Sun) placed at the top of the chart (10th), a life oriented toward public recognition and leadership. Inside, a dreamy, sensitive, artistic emotional nature (Pisces Moon) that finds nourishment in creative play and romance (5th). Meeting the world through Scorpio rising: intense, private, magnetic, perceptive; people sense depth and power.
Chart ruler: Mars (traditional ruler of Scorpio) in Capricorn, exalted. A strong, disciplined, strategic will, expressed through the 3rd house: writing, speaking, teaching, media, ideas. The life's engine is communication with authority. But in a day chart Mars is the malefic contrary to sect: the words are powerful and can cut, this strength needs conscious handling.
Angular planets: Pluto conjunct the Ascendant doubles the Scorpio theme: power, transformation, crisis and rebirth are written on the body and the identity. The underworld god sits at the door. Saturn in the 7th is also angular, so partners and rivals are a loud part of the story.
Condition: Saturn in Taurus squares the Sun from the 7th. In a day chart Saturn is in sect, so it's constructive in the long run, but heavy. There's a recurring conflict between the need to shine (Leo Sun, 10th) and the limits, demands and resistance that come through partners, rivals and contracts (7th). Relationships feel like tests; commitment matures late.
Rule of three: power & transformation (Scorpio ASC, Pluto on ASC, Leo Sun in the 10th) → confirmed. Creative self-expression (Leo Sun, Moon in the 5th, Mars in the 3rd) → confirmed.

Mythic synthesis: this is a Sun-king who must pass through the underworld. Apollo (Leo Sun at the Midheaven) wants the throne, but Hades (Pluto on the Ascendant) stands at the gate: the path to authority runs through personal crisis and radical self-transformation. Kronos (Saturn square the Sun from the 7th) appears through other people, demanding partners, hard rivals, binding contracts, who resist the young king until he earns his authority rather than claiming it. The weapon is Mars exalted: disciplined, strategic speech and writing, sharp enough to wound if misused. The Pisces Moon in the 5th is the soul's refuge, art, romance, play, where the tension dissolves. Life theme: transforming personal darkness into public, creative authority through words.

Common mistakes to avoid

Reading one placement in isolation or treating keywords as fate.
Ignoring the birth time, the houses and angles are half the chart.
Only reading the "good" or only the "bad": every placement has a light and a shadow.
Letting the outer planets' signs dominate a personal reading, for them, house and aspects matter more.
Using astrology to judge people. Astrology describes energies and potentials; it doesn't decide what a person does with them.

Beyond the natal chart (next steps)

Transits: where the planets are now, and what they're activating in your natal chart (e.g. Saturn transiting your Sun).
Secondary progressions: a symbolic "one day = one year" method showing inner development over life.
Solar return: a chart for the moment the Sun returns to its natal position each birthday, the theme of the year.
Profections (Hellenistic): each year of life activates the next house in sequence (age 0 = 1st house, age 1 = 2nd, … age 12 = 1st again); the ruler of that house becomes the "lord of the year."
Synastry and composite charts: comparing two people's charts for relationships.