It's a bad practice to crop a vertical out of a horizontal capture. For one reason, doing so loses over half the pixels your camera captures. Isn't it a better strategy to just develop the habit of composing both a horizontal capture and a vertical capture wherever possible?

LW1453 - To Thine Own Self Be True

Random Observations on Art, Photography, and the Creative Process. These talks focus on the creative process in fine art photography. LensWork editor Brooks Jensen side-steps techno-talk and artspeak to offer a stimulating mix of ideas, experience, and observations from his 50 years as a fine art photographer, writer, and publisher. Topics include a wide range of subjects from finding subject matter to presenting your work, and building an audience. 
Included in this RSS Feed are the LensWork Podcasts — posted weekly, typically 10-20 minutes exploring a topic a bit more deeply — and our almost daily Here's a thought… audios (extracted from the videos.) Here's a thought… are snippets, fragments, morsels, and tidbits from Brooks' fertile (and sometimes swiss-cheesy) brain. Usually just a minute or two. Always about photography and the art life.
Brooks Jensen is the publisher of LensWork, one of the world's most respected and award-winning photography publications, known for its museum-book quality printing and luxurious design. LensWork has subscribers in over 73 countries. He is the author of 13 books on photography and the creative life -- the latest books are The Best of the LensWork Interviews (2016), Photography, Art, and Media (2016), and the four annual volumes of Seeing in SIXES (2016-2019).