Cut the flower stems at an angle, under cold, running water, using a sharp knife or pruning shears. Cut the stems at varying length. Pick two to three of your largest sized flowers (mums are good) and cut them the tallest--they should be twice the height of the vase. As important as the flower shape and size and color is, how you cut them and place them in the vase is more important.
Place the two or three tallest flowers in the center of the vase.
Select three or four different flowers and cut them all slightly shorter. Arrange those around the tallest flowers. Repeat this process with different types of flowers and the greens. Arrange so that flowers of different types are next to each other.
Fill the vase with water. If you bought flowers from the supermarket, add the flower food.
Tie decorative bows around the vase. Use two or three different kinds of ribbon that complement the colors of the flowers and the vase.