You can throw together a quick and simple bouquet using what you find in your yard. Perhaps you'll have the need for a centerpiece during the Thanksgiving season and, if so, you could consider something like this.
Find the vase or container of your choice and add an odd number of sunflowers. The grocery stores carry beautiful fresh ones or you can select some realistic-looking ones from a craft store. I already had these, which I believe came from Hobby Lobby (don't forget your 40% off coupon!).
Now you just need a little filler. Some small branches work perfectly. I found several beneath our birch. I tucked-in three.
To complete it all, I snipped some branches from an ornamental grass. If you don't have any in your landscape, you are likely to know someone who does and I'll bet they will share. I selected five plumes.
Once you cut these and bring them into your home, they will fully open and have a "fuzzy" look. To minimize that effect, here's a tip I learned from my mother. Lightly spray each one with hairspray before cutting. I just barely "zapped" mine because I wanted some opening for texture and filler.
You could use other interesting plants, stems or twigs from your yard, depending upon what you have. Keep it simple and enjoy!