This is how I originally shot this street scene in Philadelphia's Chinatown. Given time I would have tightened up the crop in-camera but the light changed, I was with a group of other people and I had to move on. The cropped version is below.
One of the more common conceits in photography, one you'll see repeated time and time again as if it was gospel, is that you should only crop in-camera and print the resulting image full frame. I will admit that I embraced this philosophy for a while. It certainly does help you develop a disciplined approach to how you frame your images. You're a lot less likely to discover things you don't want in the frame if you make the effort to crop them out before you release the shutter.
This approach can be taking to extremes. Some photographers took such pride in their devotion to full-frame shooting and printing that they would use a file to enlarge the borders of their negative carriers and thus reveal every last millimeter of the frame. Ironically, anyone can add a faux-rebate frame in Photoshop, regardless of whether they're printing the full frame or not. What was initially intended as a mark of authenticity is now just another effect.
The biggest downside to the full-frame print approach, at least in my opinion, is that you artificially restrict yourself to whatever aspect ratio your camera happens to have rather than the one that works best for your subject. Not everything fits neatly into a 3:2 rectangle or a square. Some photographers use panoramic cameras for good reason. And let's not forget that sheets of print paper, if you're printing at all, have an aspect ratio closer to 4:5.
So don't let mindless convention hold you back. Whatever photo editing software you use, click on the crop tool, play around with it, investigate whether some judicious cropping might add power and focus to what is otherwise a "not quite there" image. Assuming the image is sharp to begin with, most cameras these days have more than enough resolution to handle even a 50% crop. If cropping an image by 50% improves it by 100% or more then I say go for it. Why not embrace one of the rare occasions in life where the more you trim off the more you get in return.