Soil tests will pin point excess levels of salts or deficiencies in nutrients and organic matter. These tests will also determine the pH, which can have a direct bearing on crop choice. Vegetables are generally shallow rooted, so soil depth is not as critical as with fruit crops. Soil management practices can be designed to modify and correct deficiencies, but are useless if the cost is prohibitive. Most crops require at least 6 hours of direct sunlight.
Leafy greens can tolerate light shade.
This is an example of light intensity. The duration of light is another consideration. Day length determines flowering, bulb initiation, and maturation in certain crops. This will affect sunlight, drainage, exposure to wind, frost pockets, and erosion. Garden rows or beds oriented east to west on a south facing gentle slope will warm up faster in the spring.