All you need to do is thread the bakers twine through the leaves and it creates a gorgeous smelling decoration. I wonder how long this would last?
If you didn't fancy using bakers twine, although why anyone wouldn't I can't imagine ;-), then I think this would look just as good with leaves stuck down with double-sided sticky tape. And because you're using sticky tape you'd also get to pretend to be Valerie Singleton or whoever your Blue Peter idol is.
Top it off with a personalised gift tag of course!