Rule of thirds?  Actually, no.  I call it “Rule of Phi”, probably best described as The Golden Ratio.

I put this under the printing section only because it has fewer articles, even though composition and cropping to me has always been more important when taking a picture.

Hasselblad H1 with Phase One p45 back

HC 50-110 f/3.5-4.5 lens at 110mm

0.6 secs at f/6.3, ISO 200