I love metal. No really... I love it in architecture, in jewelry, and especially mixed with soft things like flowers. Some of my favorite containers are galvanized or brushed silvery boxes, shown below at two different events.
For the above event I used hydrangea, tuberose, Casablanca lilies, white orchids, dusty miller and birch branches.
Same containers, used with a fall color scheme: orange pincushion protea, Friendship roses, chocolate cymbidiums, orange speckled mokara orchids, more hydrangea, kiwi vine and lots of moss.