2. To make your flowers last, clip the stems at an angle to help the flowers absorb more water. Boost their staying power by using a preservative -- an aspirin and a penny will do the trick, says Ahlvin. Change the water about ever fourth day and clip the stems again before rearranging, she adds. You should keep the water level fairly high in the vase, and keep your flowers cool, especially at night, says Kuntze.
3. Your flowers shouldn't be too much taller than the vase. If they are, they're more difficult to arrange and are likely to flip up out of the vase, says Kuntze. The good news is, short, compact arrangements are easy to arrange and are very stylish right now. "You can cut the flowers one to a couple inches above the container," says Kuntze. If you're using a mixture of colors, keep the darker colors toward the center of the arrangement. Dark colors carry visual weight, she explains, and the arrangement will look better with the weight centered above the opening of the vase. Likewise, larger blossoms should be centered over the opening of the vase with smaller, lighter colors arranged around the perimeter.
4. Start with a small vase. "If a person is designing for their own home, they'll find that a small opening is probably easier to work with until they get more practiced with it all," says Kuntze, noting that vases with small openings require fewer flowers to fill them. "I suggest that do-it-yourself-ers stay away from short cubes or round containers until they're more practiced."
5. Add personality to your flowers by looking beyond the basic glass vase. Ahlvin likes to use wine bottles, coffee cans and Mason jars, depending on the look she's going for.