Line direction is where flowers placed in the design giving the arrangement vertical direction, horizontal direction, or a diagonal line. Line materials also place curves into the flower design. Without line in a design, we would not have any fluid movement. Our eyes would be stuck and not circulate throughout the design to see the whole image we are trying to create.
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.