I found this video a time ago and I remembered about it last day, so I had a try on it and here you have the result: a BEAUTIFUL rose. It's really easy to do, just have a little patience.

http://www.youtube.com/watch?v=w2gQrAKpkSE&feature=BFa&list=PLE56E31022A565F83&lf=mh_lolz (I think it's in french, but if I was able to understand it you will be too)