Cropping in Photoshop
Chopping up your images can sometimes reveal better compositions
Why bother cropping in Photoshop? Once you have straightened the walls and ceilings and worked on your image, crop out any unwanted bits of the room. You can also do this with the externals both using Photoshop, Lightroom, ACDSee or any other software with cropping function.
It is important to do this AFTER all of the prior adjustments because if you did it first, by straightening the walls and pulling the corners about, you may be left with too little a "working space" and end up losing some details.
Don't be afraid to really close in on a particular area of interest but remember to save as a different file, keeping the original safe. The worst that this can do is give your client more images than he needs, but a bigger choice means a happier customer right?
Portrait and Landscape
Cropping in this way throws out portrait as well as landscape oriented image as in the example above. Portrait images are good for magazine covers or ads that appear in side widgets of a website for example.
Landscape oriented images are best for web pages or headers in many cases.
And don't forget, cropping images in this way also applies to any shoot you do. When photographing a subject, I tend to take a wider shot first and then crop in with the lens or camera by moving closer.
I mostly use a 30mp sensor camera and 16mm lens. The wide shot gives me room to crop in fairly close if I need to. This keeps my options open and choices varied.