pfff, 6/8, please....

I guess it depends on what you're doing and what you're after specifically.
Most of the time (current project anyway) I work intuitively and if there's something to be interpreted theoretically that comes afterwards, if at all.
When working with others in somewhat structured music, the more theoretical knowledge everyone shares, the more efficient it's likely to be. I view music theory more as a communication tool, a language, than an actual compositional tool. That's not to say that nobody composes with theory in mind or as a tool in the making, but pretty much only certain rare freaks make it work to genius level and can create music from a purely theoretical standpoint.
With that said, sometimes though, just as an intellectual exercise I guess, I'll put a few things together that I know could be structured a certain way. Like the other day sitting at a restaurant on my own waiting for a meal I composed a piece for bass drum, snare & triangle and wrote it on the back of my table mat. Don't know if I'll ever record it or anything, but I'm guessing it's the same as an architect thinking of certain specifics without actually drawing them, or something like that. It's fun to know my brain has that capacity to visualize musical elements and create them abstractly, but it's definitely not the way I compose or create music in general. I'd much rather sit down with my guitar and strum 'til the notes come to me, or toy around with samples, etc.