Keep water full.
Live flowers drink a lot of water. If you add water daily or every other day, the flower life last longer.
Flower arrangement in a vase of water (without form)
Change water often. Cut the stems about one inch in a bowl of fresh water helps flower life last longer.
Flower arrangement in green floral form.
Floral form is absorbing water, and hard to change the water. We added preservatives and nutrition when we created the arrangements. Add water full in the container helps flower life last longer.
Keep away from direct sunlight, wind or heat.
Most of flowers like cool spot (65 to 72 degrees Fahrenheit). Away from direct sunlight, heating or cooling vents, under ceiling fans, or on top of televisions or any appliances which discharges heat.

Enjoy your flowers!!