Composing an arrangment in two-steps

We are encouraged in Book 5 to make an arrangment in two steps, the first step with dry material outside a container and in the second step put it together with fresh materials in a vase. One of this arrangments was made from my students in Germany with vines and one was made in Australia with materials we could finde in the back-yard. Both are very different, but both are interesting and fun to work with.