We arrive at the true sidereal time of birth. This is used to find the signs of the Zodiac together with their degrees and minutes, which will be placed on the House Cusps around the outside of the wheel of the horoscope. Charts are consulted to determine their location at the time of birth. An oversimplified but nonetheless useful rule is that planetary sign positions indicate personality tendencies, aspects between planets reflect how various components of one's personality interact, and house positions show how the personality manifests itself in the world. Signs on an aspect with each other will interact in either opposing ways, will relate harmoniusly, or will have little effect on each other.
Aspects are especially relevant when opposing signs are on an aspect with each other.