Boo-Boo was doing this with me and picked the hotel key.
This is the little twig I picked.(sorry about the foot!)
After picking what you want you need to leave it in the sun for 1-5 minutes depending on what effect you want and the sun light it is getting. I left mine out for 5 minutes.
Then you need to wash it. Then lay flat to dry.
This is the end result! I plan on framing then and putting them up in my room. I will add pictures later to this blog.