My main criticism is to be aware of the lighting. The direct sunlight is very harsh and washes out a lot of color and casts some hard shadows. It's usually better to wait for a cloud to cover the sun, or even just wait for an overcast day to shoot flowers. You'll get better lighting and color in the flower.
Also, when you're shooting like this, you have to be very careful where you place the focus. The yellow inside of the flower isn't in focus, where I think that would be the best place to put it.
I do like the composition and the background, though opening up your aperture might give a more pleasing result for that. Unfortunately, that's the double edged sword of this kind of photography. Bigger aperture makes for a nicer background, but makes less of your subject in focus.