Flower Arrangement

So last night I went to Michael's for the cake decorating class. Just before the class started, I met Jen to pick out some flowers to decorate her cake with. She wanted some calla lilies, and some light butter colored roses, and some other small filler flowers. So we picked them out, and now I am not entirely sure what I am going to do to with them. I know that I need to arrange them in a gentle curve/slope so they will go down the side of her three tier cake. I just am looking at the flowers and not really seeing it in my head, and so I don't know where to start. I think I will need to think about this for a couple of days then start working on it. I want to have the flowers arranged long before I start baking the cakes.

Since the reception is on the 20th, I thought I would bake the cakes on the 15th. This means that I should probably get this thing together this weekend and see where I am from there. I will have to post a picture when I finally finish the arrangement, as well as when I finish the cake.