You're going to try to generate inspiration.
You've got a clear idea of what your photograph is supposed to do. You've got a little toolbox of methods:
Depth of field
Exposure (brighter, darker) Placement of subject or forms in the frame ... which is related to Camera Position
Balance of things in the frame
The way light falls
... and the way shadows are created.
Probably many other things you've noticed along the way.
Now you have to marry your idea and your method together, to make your photograph.
Alternate between these three processes:
- Think hard about what you're trying to express, and visualize specific ideas in your head (camera low? shallow depth of field?)
- Look at other photographs and pictures, looking for pictures that express something like your idea, or the opposite.
- Ignore the issue. Space out. Have a shower. Take a nap.
You can make the first one more concrete by going and trying out specific ideas with the camera and looking at the results. Ideally you can see it roughly in your mind's eye, though, and it is worth practicing doing that. The third one is really just "live your life, carry on as usual" but come back to the first two every day, or twice a day, or every other day.
If some germ of an idea shows up, or even if one does not, periodically go try some ideas out on your subject. Try some things out of your toolbox of camera technique, and see what the resulting photos look like.
Are these photos closer to what you had in mind, or farther away? Do they inspire you to change your idea, modify it a little or perhaps to reverse it entirely? Not everything will work. Even if you're making progress, there's a good chance that your ideas will change and evolve.
If you can't figure out a good way to express your concept, just pick something else and develop a new concept around that. Not everything works out, and that is OK. Give it a few days, at least, before you quit. Go around the three processes more than twice, before you give up. Is that three times, or fifty times around? That depends on you, but I think three should be a minimum.
Congratulations! You are now a Photographer! Whatever that even means. Go figure out how to use a flash, off camera. If your picture has a subject, you almost never want it in the middle of the frame. Follow my often acerbic, always awesome, main blog, Photothunk.