I guess I find some of the 'rules' helpful ... not because I am always going to follow them but because they are useful reminders (for me, at least) about the things that I should be thinking about in trying to make a better photograph.
But it would probably be better to turn this into a set of questions:
1) what is the main subject of this image?
2) how can I draw the viewers attention towards this ... through how the subject is lit and exposed? ... through the use of colour or selective focus/DOF? ... through the use of other elements of the image (framing, leading lines, juxtaposition, reflection, etc., etc.)? ... through selection of point and field of view?
3) are there important secondary subjects in the image that I want to keep within the frame?
4) are there potential distractions that I want to keep out of the frame or de-emphasise?
5) is there some overall organisation of the different elements that is more pleasing to my eye?
6) is there any potential to surprise the viewer or make some small visual 'joke'?
For me this is a lot to think about and more than I can handle most of the time ... because, most of the time, I am trying to grab 'nice pictures' fairly opportunistically without much control over the shooting conditions. When I am taking these 'snaps made with an expensive camera', something like the 'rule of thirds' (alternatively, where do I want to put my subject in the frame), is helpful alongside all the other things that are using up my limited available processing power like: find a clean background; get camera-subject-background distances reasonable; avoid amputating too many important body parts; use good enough exposure settings to get desired DOF and sharp subject; check if the sun is coming into the frame; focus accurately and hold the camera steady; what about white balance?, etc., etc.
A more experienced, better trained or more naturally talented photographer might find a lot of this relatively straightforward and more-or-less instinctive. I still find it hard work ... but I am improving and I enjoy the process ... and the proportion of my output that I find personally quite pleasing is slowly increasing.
David.
Comment and (constructive) criticism always welcome.