I had an over-abundance of flowers from a Halloween project I was doing so, I used the extra flowers to make another harvest arrangement. Normally, I wouldn't have chosen white flowers to go in a harvest design but, they were there and I thought, "Why not?" To my surprise, I kind of liked the outcome. It was a little unexpected. I found the interesting dark brown pods in my garden. They are what is left from my spent Siberian Iris. I added them to give the arrangement a different kind of texture. I'm sure there are similar things in your garden you could use also.
My advice is to never throw away any leftover flowers. Always try to find uses for them. I happened to have many leftover blossoms and was able to make a fairly large arrangement but even if I hadn't, I would have made a smaller design or a nosegay or two. Nosegays are always fun and they are great to give a friend as a "thinking of you" gift.