Cut your flowers while they are dry using very sharp pruners. The best time to cut them is early in the morning or very late in the day. Immerse the stems immediately in a bucket of tepid water. If buying them or freshly delivered, immediately place them in the bucket.
Re-cut the stems at a 45-degree angle using a very sharp knife. Place the stems immediately in a bucket of warm water. Let the roses suck up the water for several hours before placing in a vase. Strip off any leaves that would otherwise fall in the vase.
Add warm water and flower preservative to a vase and arrange the flowers accordingly to your liking. Change the solution every day. Do not display the roses in direct sunlight or in a very hot room. Move the flowers to a cooler spot at night or in the refrigerator to preserve them even longer.