When your flower arrives, just trim the stem and add water.
Re-cut 1-2” of the stems at a 45 degree angle.
Use a clean vase and clean water. Remove the leaves below the water line but do not remove all leaves along the stem length.
Check the water level daily and replenish as needed.
Don’t place flowers in direct sunlight or near any source of excessive heat.
If your flowers arrive with a floral foam, then you just need to ensure that the foam remains wet throughout the day. Just pour water on the foam so that the foam remains hydrated. In the case of an arrangement, you do not need to cut the stems.