A. The question you pose brings to mind quite a few responses, the first being what a wonderful project you will have to work on for years to come, and even then, you will never be finished.
A property that is irregular in shape adds character straight away, especially if the land slopes away to a seasonal stream or water of some type. There are so many lakes, bayous and sand pits in this area - it should be reasonably easy to find that type of situation. Trees are another big consideration. If there happens to be a stand of trees, the small ones can be rooted out to make room for the big ones to mature into graceful shade trees. Beware of property that is waterlogged. In the dry season there is not much indication of this problem but when the rains come, water will stand everywhere. Sometimes you can drain the water into a runoff drain, but you should find out about the local restrictions before purchasing the property or making any changes. Wet areas on the property can be a plus if you intend on having a water garden or growing plants that like wet roots. Likewise, a rocky outcrop would lend itself to plants that thrive in dry conditions.
Sun is the feature that plays the most important role in a garden. Many plants, shrubs, and vegetables require at least 6 to 8 hours of sun each day, while others prefer shade. So you will have to decide which areas will be suitable for shade - loving plants, and which areas you will devote to plants that prefer sun, and plan your layout accordingly. Good luck in your venture.