Think about a color scheme. A flower bed filled with every color of the rainbow and then some will look messy unless you have an exceptionally good eye for color. So before you buy plants and seeds, decide on a color scheme. A good rule of thumb is to stick to no more than three main colors and add variety by varying the shades within each color. Not only will your flower bed look more cohesive, but you’ll also be able to narrow down good choices at the garden center that much more quickly.