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.
Simple but very elegant orchid runner. Palm fronds laid down the center of the table with dendrobium orchids laid on top. You could do it in any of the colors that dendrobium orchids come in naturally- white, green or purple
Gather an assortment of cylindrical vases in various sizes and large leaves in a variety of textures and color striations. Put a little bit of water in the vases and tuck the leaves inside for a natural display that has a modern twist.