How do you write a submission?

I'm asking you. How do you write a submission? How do you write to a theme? I try to think of something that goes with the theme of a writing contest, and other stories get in the way.

Maybe I'm trying to be clever like in apples to apples where you play a card opposite to what is asked and sometimes win.

The story I can't move aside is set in a Big Brother type future à la 1984 by George Orwell. The world is entirely orderly. Or maybe it isn't. Maybe if I actually write it down, it will turn into something chaotic. Will it? I'm asking you.

Maybe I should write it down to get it out of the way, and then I can concentrate on an on theme poem.

Does this happen to anyone else? How do you write a themed submission?