I haven't shot flowers all that much. Just enough to know that it's harder than one would think.

I like the colors and comp, but whatever you want the focal point to be should be sharp. I second the call for a tripod.

Ditto on what Greg said about flower photography working best on cloudy days. If you have to shoot in harsh sunlight, try using a diffusion panel (store-bought, homemade, whatever) over your "subject." They can work wonders in the crappy, mid-day sun.