Change vase water every other day (add flower food to the new water if available). All stems should be submerged. If your flowers came in a basket or other container with foam, add fresh water every day.
Display your bouquet or flower arrangement in a cool, draft-free area. Avoid direct sunlight, which causes the flowers to die more quickly.
Immediately remove dead or wilting leaves and stems. Recut your flower and foliage stems just before putting them back into new water.