Fall bridal bouquets and centerpieces are often adorned with autumnal foliage and decorations such as branches, oak leaves, acorns and crab apples. It is often the colors, as much as the actual flowers that are important. The key to making your blooms feel seasonal without going overboard is to pick flowers like mums, astilbe, and asters, or choose petals in hues like burnt orange, yellow, and deep red.