I have just put in a silk petal window detail in our strand store:
The silk petals were bought in bulk on ebay, coming direct from china. They come in a lot of different colours and are quite sturdy and easy to use... The most time consuming part is separating the petals prior to beginning.
i found that you should lay down a wide double-sided sticky tape (you can get it at the art store), and then above this add thinner mounting tape. The double sided tape will allow you to remove the mounting tape without marking the paint on the window or leaving foam stuck to the window.
each petal goes on one slightly above the next, layered and in slightly different directions. to give a natural effect.
We began with red and moved up through pink and orange to yellow. We also chose to leave areas of the window blank to give the effect of growth and random chaos(like nature itself).
The window detail is very feminine, highly decorative and creates a strong sense of spring in the store.
We complimented the window by creating a carpet of petals around the foot of the mannequin and adding garden gnomes like snow white and the 7 dwarfs.
All in all a great and easy way to announce spring in store.