Marshall,
I find flower photography to be really demanding. It is very hard for me to make even one that is truly satisfying. Here you have a very nice bloom, with no obvious cosmetic defects. It is well focused and colorful. But there are some weaknesses: the dark shadow, the different amounts of blurring in the background, and the extraneous cactus in the right of the frame. I am not sure that there is much to do with this photograph other than to study how to do it better the next time. Time of day could make a huge difference. Certainly you could try a tighter composition, but how to take a really fine picture of this flower is not obvious to me. It's a challenge.
-Nat