Hi Ng, I know that you are very intrested in theming and you love it. But to go on like this you will get nowhere Im afraid. Sorry to say all these but its time for you to be more serious with your work if you wanna be a good themer.
First, I dont think that you are inspecting the themes of the old and good themers in detail. Its very important for you to discover the main points of what makes a good theme.
Secondly, you have to use the graphic program (ps or whatever) more better then for the moment. So go and read some tutorials.
And third, cry for help whenever you need, there are enough CTs around who can help you. These are only the first steps. The rest will come ofcourse.
Its true that you get better as you make themes but its not true that the more you make, the better you get. So dont rush your themes.
Im sure that you can do far better because you have the desire.