You have all the time to rearrange or polish your flower arrangement. The flower design should look beautiful and artistic enough before you place your filler, when the filler is already placed, it would be harder to move your things around the area or place. Bear in mind that The filler are very fragile.
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.