Trim away all leaves from the lower half of the flowers' stems. The stems should be the only thing underwater in the vase.
Hold the base of each stem under cool running water and use the scissors to cut the tip at an angle. Trim slowly to avoid squishing or tearing the stem. The cut allows the flowers to absorb more water and nutrients.
Wash and dry the vase. Add the sugar, vinegar, bleach and water to the vase and stir with the wooden spoon until the sugar has dissolved.
Arrange the cut flowers in the vase. Keep an eye on the bouquet, trimming away any rotting leaves or blossoms as soon as you spot them. This will allow the arrangement to last longer.