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 and beautiful: White roses cut short and lined up in short square glass container, taller square with taller white callas and some kind of succulent in smallest square vase - modern diy decor ideas
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.