Silk:
Silks are the easiest flowers, and require almost no maintenance. Collecting dust seems to be the largest concern. We recommend buying a silk floral cleaner, which can be purchased at most craft stores. It should be sprayed onto the arrangement following the directions on the package. For silk plants, try dusting leaves with a slightly damp cloth.

Fresh:
To keep them looking their best the longest, change the water often (every day, if possible) and re-cut the stems at an angle. Add a little bit of a commercial floral food/preservative. Some of my clients seem to swear by a half an aspirin, some sun drop or a little bit of sugar. Never allow leaves or any foliage under the water, because this helps harmful bacteria grow.

Dried:
As the flowers continue to dry out, they often become brittle, which leads to breaking or crumbling. To avoid this, never leave your arrangement in direct sunlight. You can place them in a bathroom, where steam from your hot showers will keep them from becoming too dry.