You can think of your astrological chart as a map of your internal ecosystem, similar to the map of a watershed, a national park, or perhaps a farm or piece of property you’ve purchased except that this ecosystem exists inside you. The 10 planets in your chart can be analogized to 10 people who work on the farm, each one with a different set of objectives and a particular way of accomplishing those objectives, while the 12 houses can be analogized to 12 sections of the property, each section is where certain activities, events, and processes occur.
The sign on the cusp of each house describes the themes you will experience by way of the people, events, and activities of that house. To illustrate: somebody with Scorpio on the cusp of their Third House will experience the Scorpio themes of depth, darkness, emotional courage, intensity, covert operations, subterranean dealings, and psychologically transformative processes by way of Third House endeavors such as communication, reading, writing, speaking, and short journeys. Somebody with Scorpio on the cusp of the Seventh House will experience Scorpionic themes within the context of Seventh House endeavors such as marriage, partnerships, rivalries, anything where they are equally matched with another person.
Put another way: You are *every* sign, not just your Sun. That particular Sun sign you just can’t get along with it? Well guess what? At least one of the 12 Houses in your chart is ruled by that sign! (The same goes for your favorite sign.)
Your immediate persona, impact on the immediate environment (Same as the Ascendant), how people experience you when you walk in a room.
Your skills and talents, how you survive, how you make money, the stuff you own, your self-worth, your values. The house most directly connected with nature, the outdoors, physical sensations/sensuality.
Your peer group, the immediate neighborhood, your mind, speaking, writing, communication, perception, avenues of communication such as the phone and internet, also aunts and uncles in some astrological traditions.
The deepest, most undefended part of you, your concept of home and family, hearth and tribe, your inner heros and shadows, also the physical home. The contents of your fourth house are known only to you, few if any others are ever allowed to see or know them. You might see somebody you find attractive (1st house), start dating them (5th house) a few weeks later, sleep with them shortly thereafter (8th house), even end up marrying them (7th house) a few years down the road but you won’t get to know their 4th house for at least another 10 years, if ever. So while the fifth house rules romance and dating, 7th house rules one-to-one relationships, the 8th house rules sex, in many ways the 4th house is the house of *true* intimacy.
Creative self expression, romance, debauchery, sports and athletics, fun and games, anything involving speculation (including having children!). Planets and placements here indicate how you have fun, how you express or fail to express joyfulness.
Your daily habits like diet and exercise, the daily grind at the workplace, daily responsibilities, your physical structure, any problems that interfere with your ability to express yourself such as health problems often show up here.
Marriage partners and open enemies. (Yes, they are ruled by the same house in astrology) Any relationship you could honestly call a “1-to-1” partnership be it a marriage partnership, business partnership, or even an equally matched rivalry brings out both your best and worst qualities. This is also the house whose qualities you are most likely to “project” onto others.
Sex, death and other people’s money. (Yes, right after marriage). How you transform, how you regenerate. Money or resources you get from other people whether they are relatives, sex partners, financial institutions, etc. Your unconscious mind.
Philosophy, religion, law, publishing, higher education, travels to other cultures, encounters with the foreign/exotic (including foreign or exotic ideas). Where you will find your in-laws and other exotic creatures who shake up your life. Your model of reality, of the “big picture”. If you were to create a religion or life philosophy, it would likely be based on placements in or to your 9th house and/or your Jupiter.
Your career status, public image, your role in civil society, your reputation, your credit score, how you relate to “the man” and “the establishment” and how they relate to you. The type of social role or job title you find impressive, both in yourself and in others.
Your goals, dreams, kindred spirits. Friends you choose, even if they are not peers in terms of race, age, economic, familiar backgrounds (those are in the 3rd house), the “crowd” you run with, your social network, (impersonal) friendships, facebook friends, social causes.
The collective unconscious, the ancestral line, psychic and spiritual development. On the physical plane, the 12th house rules all institutions and settings involving seclusion ranging from prisons to mental institutions to healing clinics to nature reserves.