Use big containers. A few large pots create a lot of drama; a dozen small ones go unnoticed.
Select one primary color. Go with one hue—say, orange—and use variations of it for variety.
Go vertical. Line up a row of imposing tall, narrow pots along a bare wall.
Keep it simple. Use just a few plants with strong textures—the restios in orange pots along the fence, for instance—to accent in streamlined style.