Preserving flowers is an easy and rewarding task. The first step in the process is drying them in a way to preserve their color; the second is applying some sort of preservative. You can increase your chances of success by picking blooms just before they mature (otherwise you run the risk of losing petals during the drying process) and selecting hardy flowers like roses, hydrangeas or mums.
Drying the Flowers
Clip healthy blooms just before they are fully mature. Make clean cuts and make sure each stem is at least six inches long
Strip stems of excess foliage, although if you like you may leave a ring or two of leaves just below the bloom.
Hang flowers upside down from a wire coat hanger by connecting them with dental floss or fishing line. You may either bundle flowers with a rubber band or twine, putting one bundle on either end of the hanger, or hang each flower individually. Make room in your closet or pantry--optimum drying conditions are warm, dark, dry places--and let the flowers dry for two or three weeks.
Preserving the Flowers
Tie a strand of fishing line or dental floss to the end of each flower.
Holding the string so no part of you touches the upside down flower, spray with an aerosol hairspray, acrylic spray or commercial preservative. Art stores will generally carry several brands. Make sure you spray lightly but cover all parts of the flower.
Tie the loose end of the string back to the wire hanger and let dry overnight.