Thanks Fotoartist - I can see the petals look a bit rough around the edges and may have another go just for the experience.
If you are using Photoshop the refine edge tool is pretty amazing. You make a rough selection then choose select and mask. You can view it as marching ants or to reveal your layers below. Get close with the brush tool then switch to refine edge and paint with the + on your edge. It looks for contrasts. Switch back to brush to fix problems. Output can be to a mask or to a selection or to a new layer with mask.