Do you choose portrait or landscape mode for your photography, does it matter?
Try to get into the habit of taking 2 images for every scene or object you photograph. I learned to do this when shooting stock photography. What you use the image for now may change in the future and if you have both orientations, you are laughing.
A portrait image, if one day you intend to sell it as stock, will work well for magazine covers etc whereas a landscape image will work better for a web page and both will work for greetings cards…spread your bets!
So when you arrive at a point where you are about to click the shutter, ask yourself if the shot would look better landscape or portrait, or both. What shape and orientation is the main subject? Try to compliment it with your composition and orientation.