Looking at your picture: your application is not beautiful or ugly: it does not exist (may be exist in real life, but there is nothing on the picture). The standard frame is not yours, for font is not yours. Only the letters in the title and menu are yours, but the text is not very much of design. It looks like MDI, and this is simply unacceptable: who you MDI? nearly everyone understand its very inconvenient.
At the same time, if you want to "beautify" the "content" you show right, you can only make it worse. You cannot improve the empty place. Really beautiful design never draw a single pixel just for "beauty", every single pixel should have its functional purpose.
It you start from this point in your search of beauty, you have a change to approach it. I think so.
Would you like to take a look at two my past Answers to this Question:
GUI Apperance - C#.Net
Just to give you a basic idea on what I'm talking about…