When photographing wildflowers, there are several things to keep in mind in order to produce the best results. First of all, get close. I'll often get as close as my lens can focus. Then zoom in. Fill the frame with the flowers, if possible. Also, consider the orientation of the flower. For the yellow one above, it was best shot from above. Most wildflowers, however, are best shot from the same height as the flower itself. Get down low. If the ground is muddy or you're unable to get your body as low as the flower, hold your camera down there and shoot several exposures. Over time you'll become comfortable aiming your camera without looking through the viewfinder.
Consider the background too. For the shooting stars, I sought those that were partly in the sun, but had a shady area behind them. This really helps the flowers stand out. Also, make use of shallow depth of field to create an unfocused - or Bokeh - background, as I did with the white flower above.
Finally, consider your composition. Do not center the flowers in the frame. Either when shooting or afterwards when you're in post-production, crop the image so the main flower in your image is off-center and above or below the mid-point of the frame.
