Cut the floral foam to fit the inside shape of the wall basket, then glue the foam in place. The top of the foam should extend out of the basket by approximately 2 inches.
Cover the foam with moss and secure it using hot glue or floral pins.
Insert the greenery into the foam. Place the largest stems in the back of the foam and the smallest toward the front. Allow some of the greenery to hang over the front and sides of the basket. The greenery should fan out in all directions so that it will be visible from all angles of the arrangement. If you are using more than one type of greenery, insert all varieties before you begin to add flowers.
Place the smallest filler flowers in the foam using the same fan pattern you did with the greenery. The small flowers should have an even spacing around the arrangement. The small flowers should have a range of stem lengths. Some may be longer than the greenery, while others are slightly shorter.
Place the largest flowers into the arrangement so that the blossoms are visible on the front and sides of the arrangement. If you have more than one type of large flower, place one variety, then the next, to ensure that you space the flowers without overcrowding an area.
Insert medium-sized flowers into any open spaces in the design, keeping the design balanced on all three sides of the arrangement. As with the small flowers, the medium and large flower stems can vary in length and spill over the basket sides.
Place a strip of ribbon through the arrangement or add a bow to the front to complete the design.