You may start by placing your foliage that you will use in a water vase. You have to make sure that you keep it around the lips or edges. Stick with the plan to place them the lips or edges of your water vase with a layer of your Foliage. When it is too big or too thick, it ends up detracting from your cut flowers. And if it is small or too thin, visual contrast will not show.
Place your ornamental cut flowers into your water vase, make sure that you put it one by one. If it's going to be a design or floral arrangement against a wall or flat surface you have to put the tallest or longest cut flowers at the back. If your design or flower arrangement will be visible from the sides place your longest or tallest flowers in the middle. Begin with the longest or the tallest, and then go out to the lips or edge of your flower container. Now, take time to look at your flower vase, is it beautiful and pleasing to see? Did it turn out to be symmetrical? Is there a spot or an area that needed to be filled in with more flowers?