Floating Flower Tip - Most flowers float pretty well on their own until they start to pool with water and slowly sink. For a longer lasting centerpiece, use bubble wrap to make little skirts for your flowers.
DIY Pinecone Owl by broogly: These adorable pine cone owls are a fun autumn craft for kids of any age. You can combine this craft with a nature hike to find the pine cones, acorn cups and leaves used in the activity.
Pine Cone Hedgehog Ornaments - There’s no tutorial for this, but you could make your own by slicing a pine cone in half and drawing little faces and paws with a Sharpie. - 62 Impossibly Adorable Ways To Decorate This Christmas
Orange-o-lanterns! (No link, just wanted to remind myself of the idea). Cut the top of the orange, hollow out (be sure to not cut lining too thin or it'll melt your candy). Make faces for the oranges and fill up with goodies!