Your fresh flowers will need to be hydrated upon receipt.
First, prepare buckets with filtered water to preclude the presence of chlorine. If flower food is available, mix the appropriate quantity into the water. Next, proceed to cutting 1/2- 1 inch off your flower stems at an angle (with a sharp knife NOT scissors), and immediately place them into the water filled buckets. As a tip, cutting stems under water helps prevent bubbles from forming inside the stems.
Once all flowers have been trimmed, keep your flowers at a cool temperature out of direct sunlight and in a location with good airflow. Most non-tropical flowers do best in temperatures hovering near 45 degrees and when placed in shaded areas. Tropical flowers, on the other hand, require temperatures above 45 degrees.
Hydrangeas, Iris, Gerberas, Rannuculus, Lisianthus, and Freesias: These flowers are water thirsty. Keep them in water as much time as possible since they require higher hydration levels than other flowers. Add flower preservative and change water periodically.
Snapdragons: Keep upright and away from warm surfaces.