It's important to select either the right pot for your plant or the right plant for your pot. Take into consideration the size of plant and how big it will grow. If it's an annual, you must only consider its growing potential for one season. Perennials, however, have much more time to spread their roots and are more likely to outgrow their surroundings. Regardless of which kind you have, follow its specific planting instructions. As a rule of thumb, the height of a plant should equal the depth of the container. Small pots tend to look best with simple plant designs in basic colors.
Choosing the right plant also means matching its look to its container. Informal pots like handmade terra-cotta containers or wooden barrels tend to look best with equally unassuming plants, such as wildflowers. In contrast, a manicured shrub inside an elegant urn-shaped pot would present a consistent formal aesthetic.