There are no hard and fast rule around photography but there are certain things that will help make the photo standout or be more pleasing to the eye. The golden ratio is one of them and can be a useful idea to understand.
To be more specific your daisy photo at
http://samaravsalma.deviantart.com/art/Daisy-138887355
The photo is perfectly fine with the subject in the middle however you also have a lot of clutter i.e. the grass passing in front of it, the other daisies that have lost their petals. This takes points away from the photo and makes it very not very interesting. Also the angle you took the photo is slightly high which doesn't give the photo a 3d feel and everything feels very flat. The lighting and colours are again very muted which doesn't really help the flower standout. Lastly you can probably get closer to the daisy.
I have attached a similar photo of a daisy I have in my library. It is not very good but it does show you what I mean in a more visual sense.