I rarely crop photos, mostly I compose them like I see them in the viewfinder or on the rear display of my camera (and sometimes I decide on a square or on a 16:9 TV-like format, which both can show before taking the shot).
But there are times when some other aspect ratio than the native 4:3 one fits better. I like 5:4, especially in portrait orientation (and for portraits), it has that large format look somehow. And when I crop in post production, I tend to do it only on one side, and into the “classic” formats. Here are some shots from today, all in different aspect ratios:
Fairies (or mini models with wings?). Cropped 3:2 during post.
Chilies (there are still some left). Uncropped 4:3 full frame from my Four Thirds sensor.
Peanuts, roasted and salted. Cropped 7:6 during post.
All taken with my Olympus E-PL5 camera and the Panasonic Leica DG Summilux 25mm/1.4 lens, at apertures 4, 2, and 2, and with ISO 800, 200, and 800.
Thanks for viewing.