Everybody has at least one old item at home. Instead of throwing it away, you can recycle it and bring it to new life. For example, create some nice garden decoration from old items. Old furniture, your grandpa's old bike, shoes with flowers in it, even a boat - use your imagination and create beautiful and original decoration.
Hopefully, your creations will make your guests recycle and reuse more and more. This is not only useful for all of us but also a good way to contribute to the green idea.