Before putting the flowers in water, make a diagonal cut about 1 or 2 inches from the bottom of each stem.
Strip the leaves from the stem up to the height of your vase; the foliage should never come into contact with the water. Contrary to popular belief, the water should make contact only with the stem, not the leaves.
The water level in the vase should be as high as possible, from the bottom of the stems and according to the size of the vase. You can add a small amount of sugar as food, and little vinegar to eliminate water bacteria.
If possible mix a floral preservative into the water.
Do not place the flower arrangement in a sunny place; it is preferable to put the roses in a cool and shady place.
Add some more water depending on the rose consumption, or change the water every 2 to 3 days if you wish. Try to maintain a constant level of water until the roses wilt