Some of your photo's have their subject in the centre, try putting them more to the edges of your picture. See:
Rule of thirds - Wikipedia, the free encyclopedia
Also, the picture of the bridge isn't level (the horizon is lower on the right). And for these kind of pictures (outside, sunny weather) a CPL gives your pictures a much better contrast, and it removes the glare.
For the flower, you used the following settings:
ISO: 1600
Shutterspeed: 1/90 sec.
Aperture: 38.0
Focal Length: 55mm
The aperture is very, very high. You would have probably had a more pleasant result with a lower ISO and a lower aperture. Also, a lower aperture results in parts of the pictures being out of focus, which usually works very well with macro shots to focus the attention on, for example, one particular flower.