There are lots of perennials that are great for arrangements, but I don't put them here because we rotate the vegetable crops and that would impede that a bit.
I have found that when it's hot outside, it is best to pick flowers and herbs in the morning. They've had overnight to rest and recuperate from the stress of the summer heat.
This is my harvest bucket. Fill it with water and as soon as a flower is cut, it gets dropped into the bucket to rest and take up water. I try to leave them resting for at least 2 hours and sometimes much longer.
If I buy flowers at HEB or Sam's, this is basically my same procedure. Trim the ends and let them sit in a bucket of water for a nice drink.
Today, we just made small arrangements in glass jars. Dotted along the dining room table, they will add nice touch for a Tex-Mex Dinner