The secret to the appeal of dried floral arrangements is variety. Add interest by harvesting your fresh flowers at different stages of development. From the time buds crack open until full bloom stage, the flowers themselves will create the diversity you need as long as they haven't faded yet. Consider also that nearly any plant material can be readily dried and used to complement the flowers in your arrangements. Foliage, berries, seed pods, grasses and cones can add appeal and interest. This simple process for drying flowers will effectively preserve them, and any beginner can do it. All you'll need to make the plant drying mixture, or agent, is sand and boric acid, which are both inexpensive and readily available materials.
Use a clean, sharp knife to cut flowers for drying anytime they're available. Choose unblemished, insect-free blooms after dew or rain has evaporated from them. Plunge cut stems into water right away so they don't wilt while you're collecting materials.
Combine 3 parts boric acid with 1 part clean, dry white sand to make the drying mixture. Add about 3 tbsp. noniodized salt per quart and mix thoroughly.
Cover the bottom of a shallow box or other container with about 1 inch of the drying mixture.
Place your flowers on the surface of the drying mixture in a single layer with an inch or two in between each. Position flat flowers such as pansies and daisies face-down. Set flowers with lots of petals--asters, marigolds, mums, zinnias--facing upward. Place spiked blooms like hyacinths and snapdragons horizontally.
Sift the drying mixture carefully between your fingers to completely cover each flower. Store the flowers in a warm, dry location where the container won't be disturbed.
Slip your fingers into the drying mixture under a flower after three to five days. Scoop it gently upward and check the texture of the petals. They'll feel like paper when they've dried to perfection. If the flower isn't quite ready, return it to its spot and cover it up again. Drying time will vary depending upon flower variety and atmospheric conditions. Just keep checking until the results are satisfactory.
Scoop dried flowers from the mixture one at a time and gently shake any remaining drying agent from them. Coat each with hair spray or lacquer to seal them.
Preserve any leftover boric acid and sand mixture for future use. Spread it evenly in a baking pan and bake at 250 degrees F for an hour. Allow to cool to room temperature and store in airtight containers.