Select a vase that is about half as tall as your flowers. This will ensure that the flowers do not tip over the sides or fall out of the vase, or become too squeezed together if the vase is tall. If you really want to use a taller vase, fill the bottom with some pebbles or even marbles, until you've reached the correct proportions. Your vase will also need to be wide enough to hold all the flowers you want to put in it.
Choose your flowers. Pick several different types of flowers that all have a similar color scheme. For example, you may want to choose yellow and white flowers. Or, you could pick flowers in varying shades of pinks. Pick flowers that have several different textures, so that your arrangement is interesting. You'll need some tall, mass flowers, as well as some line flowers, which are flowers growing up a tall stalk; and some filler flowers, which are smaller flowers, along with some dangling or vine-like flowers and some greenery.
Cut the stalks of all the flowers and greenery at an angle. This will help the flowers drink water. Remove any leaves from the flowers and greenery that will be below the level of the water in the vase. Leaves pollute the water.
Add greenery to your vase. Greenery can be any leafy or non-flowering item, such as ferns or eucalyptus. Greenery acts as a base for all the other flowers, creating the beginning structure. It will appear as filler later.
Insert the mass flowers into the vase, along with the line flowers. Mass flowers, also known as structural flowers, usually only have one flower on each stalk. They include things such as roses, lilies, or tulips. Line flowers include flowers like snapdragons and gladiolus. They add texture to the arrangement. Add uneven numbers of each flower. Uneven numbers usually look better and more natural than even numbers. Disperse each type of flower evenly throughout the arrangement.
Shape the arrangement so that it is somewhat dome shaped, with taller flowers at the top and somewhat shorter flowers near the bottoms and edges. The shape does not have to be perfect or symmetrical. This shape, though, will allow all of the flowers to be seen from all angles.
Insert the filler flowers. These are smaller flowers, such as baby's breath or aster, which fill in any gaps and give the arrangement a fuller look.
Add spilling flowers along the edges and bottom of the arrangement. These flowers spill away from the main arrangement, adding interest and texture.