How to improve this phoyo?

To appreciate sharpness, look at your pictures at 100%. To detect artefacts, use 200-300%. To appreciate the exposure, look at the entire picture and look at the histogram. Sometimes, even that the histogram looks equilibrated, the image is too dark or too bright.

With your picture, there are 2 major problems:

• The picture is out of focus where it counts: the blossom!
• The picture is underexposed, as a look into the histogram is telling us:

   

Start with depth of field. Too much is out of focus.

View your Photos at a high magnification.