You may like a lot of different plants, but when designing your own landscape, you may not be sure how to group them. There are, of course, aesthetic considerations (please consult landscape design for beginners), one of the most basic of which is that, in planting bedding plants, you'll produce a greater effect if you mass like plants together (rather than installing one here, one there). Even in planting foundation shrubs, the "rule" is to plant like shrubs in groups of 3 or 5.
The artistic angle may be the fun part of designing your own landscape, but you can't allow your artistic eye to be sole arbiter when it comes to site selection for your plants: there are also practical reasons for grouping plant A with plant B, rather than having it grow next to plant C.
The rule of thumb for the practical side of designing your own landscape is to group plants with similar requirements together. This includes sun and watering requirements. Grouping them together will reduce maintenance for you (saving you from dragging the garden hose around unnecessarily, etc.). For help with such grouping, please visit landscape plans (if you haven't already done so), where I provide examples of plants that "go together" based on their need for sunshine, tolerance for shade or wet soils, or resistance toward deer pests.
I discuss site selection in more detail in the next FAQ....