Here's a classic but a goodie for fall: These wheat sheafs or sheaves or bundles or whatever you want to call them are so plentiful and inexpensive ... or free, perhaps, if you live in Kansas? I created the above design quite a few years ago using a store-bought bundle. I cinched the center with a rubber band, fastened a shimmery but shear gold ribbon over the band and shaped it into a pretty bow. I tied a thin gold cord around the same spot then hung a silver and gold cross pendant from it.
The photo below shows another version of a wheat sheaf done for a traditional dining room centerpiece at Thanksgiving. It uses the same style ribbon for a bow, but has a red jewel beaded cross pin for the accent:
AND, this whole ribbon + cross idea can be done for any time of year because it will work with any kind of "bundled" natural thing: other grains, decorative branches, and reeds:This bundle is just green reeds tucked into a corner of a stairwell landing. They stand about 3 feet high. No matter what your material is, just fasten your attachments a little above center to make it stable and able to stand on it's own. Fan the stems out by giving them a little twist, then tap down to make the bottom flat.
The beaded cross shown above is a pin and it came for Hobby Lobby for $3.