What is the best way to plant a nice planter?

You need to allow for the thrill, the spill and the fill in a great looking planter arrangement. Something bold or tall for the thrill in the center or back, in this case, the red/orange calla lily.Then something that will spill over sides, in this case, sweet potato vine and wavy petunias. Lastly something that will act as filler for the base, in this case, hite bacopa. Some other fillers that are great are lobelia and allysum.