two years for a thread
I was reading before and I agree to curl the petals before you close the bottom, also you can fold down the main petals in half and that helps to keep them curve.
also to humblestumble, maybe a good tip is that you have to enclose one over the other in a counterclockwise way, but the last one is tricky nevertheless.
Anna's question is real

, but I think we are talking about the Chan's diagram. Anyway, maybe you should like the last post in my blog about the rose, basically it suggests that the 22.5º grid is not necessary to fold the Chan's New Rose.
many regards and sorry for my crappy english.