Once you place your flowers in room temperature water, they will open up beautifully.
It is best to keep cut flowers on cold temperature (below room temp. 12-16 C) until you arrange them. While the bulbs are closed, they are less vulnerable.
Recut one centimeter of the stems diagonally when placing in water and repeat this every every second day when you change the water. Basically, you don’t need any chemicals to add to the water because the chlorine added to tap water is enough. All flowers respond well to changing water regularly.
With branches and foliage, remove all excess foliage before placing in cool water. Every leaves should be above the waterline.
Cut orchids need to take great care in handling them, as petals damage easily. All orchids benefit from reasonably warm conditions.