For instant gratification in crafting, nothing beats drying flowers in the microwave. The materials are inexpensive, with the exception of silica gel--which can be replaced by either kitty litter or a cornmeal-borax mix. The process takes only a few minutes of preparation and heating, and an overnight waiting period for the drying process to finish. The microwave technique results in "dried flowers that look fresher and more colorful than those obtained by other methods," according to the University of Missouri Extension (UME).
Pick flowers in the morning, after the dew dries. Save especially large or thick-petaled flowers like roses or hydrangeas for another kind of drying; they don't respond well to the microwave method.
Sort and pick over the flowers, removing insects and dirt particles. Discard any diseased or poorly-shaped flowers. "Damage only becomes more obvious after drying," notes the UME.
Remove leaves from the flower's stems. You may end up clipping the stem for your craft later on, but it's reassuring to have the option of a stem for wreaths and vertical arrangements.
Prepare your desiccant. Choose either commercial silica gel, kitty litter (the bag should call itself "dust-free" or "dustless") or a combination of equal parts white cornmeal and borax.
Pour 4 cups of desiccant into a deep-sided microwave-safe container -- either a casserole dish or bowl.
Remove a portion of the desiccant roughly equal to the depth and width of your flower.
Place the flower into the resulting hollow in the desiccant, and gently cover the flower with the rest of the desiccant.
Make a second depression for another flower, if room permits. In general, dry flowers in batches of two small flowers or one large flower.
Put a small cup of water in the microwave. Steam from the heated water prevents over-drying of the plant material.
Place the casserole dish or bowl containing flowers and desiccant into the microwave. Do not cover the container.
Heat small or thin-petaled flowers for 1 minute and larger, thicker flowers or flower pairs for 3 minutes. If the first batch doesn't seem dry enough, or is too dry, adjust subsequent batches accordingly.
Remove the bowl from the microwave and wait at least 12 hours for the desiccant to cool and completely absorb the plant material's moisture.
Scoop the flowers from the bowl and gently shake or blow the remaining desiccant from the flowers. Remove stubborn bits with a small paintbrush.
Spray the flowers with hair spray or floral lacquer. Microwave flowers absorb more moisture than those dried by other methods, so the additional protection is important.