1. What is the purpose of the arrangement?
How will it be viewed?
How large should it be?
What shape will work best?
What style? Formal/informal, loose/buttoned-up
2. Choose a container or vase:
Tall? Short and round? Urn-shaped?
Color/texture of container - formal/informal
3. The answers above will help determine the structure of your arrangement - round? One-sided? So people can talk over it? For the mantel? Table?
4. Choose your greens and flowers
Not only colors, but shapes and textures, large, small - again consider the setting in which it will be viewed.
Colors: warm greens (IE Warm -- yellow-green, green work well with apricot, reds, yellows, magentas, blues - clear colors. Cool -- softer gray-greens go well with pinks, purples, darker reds, whites.)
Monochromatic is soft, peaceful - bright colors are exciting.
5. Based on all factors above, you begin with structure/form: (Vase arrangement can/should be 1.5 - 2 time the height of the vase. Just a general rule of thumb.) Look for balance - weighted appropriately at the base, using dense flowers / strong colors there.
6. Whatever form you choose,
Vary heights, up and down
Vary depths, in and out
Cross the edge of container with softness
Stiff vs. arching - nice to mix for graceful look
Flowers and foliage for cutting gardens
Alchemilla Mollis (Ladies mantle)
Sunflowers - annual and perennial
Ornamental grasses - green, varigated, pennisetum rubrum
Lysimachia clethroides (gooseneck loosestrife)
Monarada (Bee balm)