Anyways, the point is that pretty much anything you can do in terms of technical/photographic choices has some sort of visual effect.
Good composition is about assembling a set of visual effects to create a picture that has the result you're looking for. There's a lot of general discussion available about what sorts of things one visual effect or another has that one can read about in books on painting, and early texts on photography, but ultimately it's about the gestalt effect produced by all of them that appear. Yellow is usually warming, a happy color, a good feeling color. But not always. Shove it in with the right combination of subject matter and other visual effects, and it might feel menacing.
It's not bad to have some guidelines and some ideas about how things work.
But ultimately you're going to need to deep visual vocabulary, and the technical mastery to pull the elements of that vocabulary off (that part's pretty easy, the harder part is simply knowing what is possible). When you have that in place, then you can start to visualize ideas for rendering whatever it is you want to show, and, if you're lucky, some sort of inspiration will strike and you'll know what to do to get the effect you want.
The option is to do what most people do (including plenty of internet-famous photographers) which is to simply ring the changes on standard compositions, and hurl masses of technique at them to attract the adulation of the gearheads. Which is a whole lot easier to monetize, I have to say, then actually taking interesting pictures. And, obviously, a lot easier to do as well.
