Just because it's November, doesn't mean I have to give up my passion for pumpkins ... right? This white-on-white centerpiece might just be my favorite (I LOVE dahlias, too):
Step-by-step instructions here. And here's another idea for a pumpkin-related, Thanksgiving centerpiece:
Instructions from MSL:
Anchor tapers inside mini pumpkins to make centerpieces. Cut a hole inside each pumpkin with a utility knife, and then carve out space for candles with a melon baller. If desired, stack 2 and secure from inside hole with straight pins. With adhesive putty, affix tapers inside gourds and pumpkins to leaves that cover overturned pie plates.
Good thing I bought all those pumpkins ...