From pastel to Oil

I recently started a new oil. Earlier I posted the pastel sketch that I am working from. I also have the dried flowers as reference, but find most of the painting is coming from my imagination, especially the composition. As always working this way I am usually not sure which direction the background will take. I'm still trying to work that out in my mind. The pastel sketch has a mid tone lavender in the lower half. It was suggested to me to make that darker, but I need to work out more of the leaves in that area to figure out what to do there.....any suggestions?

New Start

I am in the middle of framing the Hydrangea painting and getting it ready to be shipped off to Texas next week. I will post a picture of the finished piece in a few weeks.
Many times before I start a new flower painting in oil I will do a pastel to get composition and color ideas. So I thought I would post the various stages of this new Zinnia painting.