To begin officially planning the layout, you need to find the space and shape you are working with. I placed the suitcase with the open side down onto large scale paper and traced around each side. I then removed an amount equal to the width of the metal frame from the traced shape to find the finished size/shape of the inside of the case. I marked where metal clips were so I could work and build around them. At this point I moved to the computer to create my layout but you could very easily plan your shapes on the paper pattern you just created (or chart it on graph paper).
Also, measure the depth of each side of the suitcase. A depth adjustment between the two sides of the cases may need to be negotiated. To fit the glasses on the left side of the case the shelves needed to extend past the edge of that side of the suitcase. The shelves on the right side need to be less than the depth of that side to accommodate the extra space the left side shelves need.