#1 I love the color contrast between the orange of the flowers and the blue of the sky, but maybe more flower, less background. Or possibly throw the background more OOF like Samanax suggested.
#2. Again I agree with Samanax--pick a flower and get closer to make it your main subject.
#3. I like this one also, but the flowers that are in focus are 'stuck' to the right side of the frame. Pan the camera to the right a little bit to give the petals a little more edge tension.