Look for a single focal point flower in a flower arrangement in a low container, offset by drooping line flower branches on either side. The length should be twice the width, as well as symmetrical with the same number and assortment of flowers on either side. This will be a horizontal flower arrangement and it will typically be used as a centerpiece. Freely interpreted horizontal arrangements can be asymmetrical.
Identify a vertical flower arrangement by the use of long-stemmed flowers such as rose, carnation or tulips in a tall arrangement with filler flowers such as forget-me-nots to provide balance. The stems of the tallest flowers should be three or four times the height of the vase.
Notice if the arrangement incorporates both vertical and horizontal lines in an L-shaped flower arrangement. While this will not be symmetrical, it must still look balanced. Shorter flowers may be fitted into the container at different angles along with the tallest vertical flower, while the low-lying horizontal flower might be accented with shorter flowers also sticking out at various angles from the base. The overall shape should resemble the letter L despite these variations.
Look for an overall triangle shape, where the height of the arrangement is more than the width. This will be a triangular flower arrangement, which is a popular arrangement at weddings. The focal flowers should be at the heart of the arrangement as well as lower down for weight and balance, surrounded by filler flowers that maintain the triangular shape.
The inverted T arrangement is similar to the triangle, except that the lower side flowers are not as pronouncedly extended and may appear more tucked in, like star arms.
Notice that oval arrangements will not be 360 degrees around. The brightest and tallest flowers will be in the center, with the other flowers reducing by degrees in color and size the farther out they extend.
Find curve-shaped flower stems in crescent arrangements, such as the flexible-stemmed gladiolus or carnation. These will produce the asymmetrical, curved moon shape, which must be balanced and proportional in shape and weight, for stability. A bowl-type vase would work well with this arrangement, with the focal flowers positioned low in the bowl for depth and balance. Crescent arrangements can be used for coffee table decoration.
In fan-shaped arrangements, look for long, strong-stemmed flowers such as gladioli and ester, which are necessary to maintain the distinctive flared shape. It may be flared above as well as arrayed around the edges of the container.
Look for an all-round shape, in which the flowers are uniformly distributed to make a dome arrangement. The container should be about medium height.
See if the flower arrangement contains an S-shape, which is sometimes used as a focal point within other flower arrangements. Stems should bend gracefully both above and below with the focal flowers following the lines of the curves to form what is called a lazy S. This will be the more complex Hogarth's S arrangement, which may require professional virtuosity.