"Everlastings" are flowers and plants that can be preserved (usually by drying) without loosing their beauty. Being preserved, dried flower may often change it's shape and color, revealing hidden features. Leaves may cup; grasses and stems may twist in bizarre patterns; colors may unexpectedly alter.

Lots of foliage, seedpods, berries and vines are used in dried flower arrangements. A bunch of autumn leaves with their joyful colors can be just as beautiful as a bouquet of fresh-cut flowers.
The most common way of preserving flowers is to let them dry on the plant or to hang them in a dark, dry, and warm place. Today's special techniques of preserving flowers range from freeze-drying to using silica gel and glycerine, however, there exist some easy techniques that might be used at home. To preserve a fragile fluffy dandelion one can sprinkle it with hair spray and replace the stem with a wire, when the flower dries. Preserving flowers or leaves, one can simply press them between the pages of a book. Pressed flowers are frequently used for making postcards or framed wall pictures. 

Dry flowers are made of natural materials and need special care. They don't like sunshine, however artificial light doesn't harm them.

Never put dried flowers on a windowsill or on heating radiator. Check the air humidity level. If it's below 40% the flowers become fragile. High humidity (over 70%) might cause development of fungus.

Be aware that some berries and fruits, used for dried flower compositions, can attract moths. You might have to use special sprays and chemicals.  

Use a vacuum cleaner or a soft brush to clean dried flower arrangements.