Actually there are NO rules to art - that would make it mechanical, math
Rules are for art critics and art instructors to give them something to talk about; technique is about how to achieve what YOU want and has nothing to do with rules, teaching (and I am a teacher) should be aout how to convey what YOU want to convey - the subject
Photography is an art and art has no rules, just the desire to communicate and the rest of it: diagonals, leading lines, s curves, ad nauseum is all mechanical techniques once you actually have a composition, critic words, carping
You should just make a picture that appeals to you yet conveys what you saw to others. Rules are math, if there were actually rules we could turn loose a robot (i.e. google earth) to take all the pictures that ever could exist; but art is not about rules; art Appreciation is