Training wheels for your camera
Magnum photographer Robert Capa is well known for having once said, "If your pictures are not good enough, you're not close enough." In other words, fill the frame with your subject.
This is a good thing to keep in mind when engaging in documentary photography, street photography and when photographing people in general, particularly when using a side angle lens.
Fill the frame with your subject. But don't fill the frame too much.
Like other so-called "rules" of photography, Capa's axiom is not carved in stone tablets and delivered by Moses. There are times when you can get too close to your subject matter.
Your subject needs room to breathe around the edges. If you get so close to your subject that it is pressing against your frame lines, you are too close; that goes double if parts of your subject are cut off by the edges of your viewfinder or rangefinder frame.
How much breathing room does your subject need? That's not easy to quantify; it's something that you learn to recognize. If your subject crowds the frame lines, you'll come to recognize that with time; if you compose with too much breathing room around the frame lines, you'll recognize that, too. I tend to think in terms of 5% of the frame width or height as being a little too close and 10% being a little too much breathing room; somewhere between 5-10% looks about right. To me.
As with all the "rules" of photography, your personal vision, your personal composition aesthetic and your personal outlook should transcend the rules. If you cling to the rules, you will create safe images; with time, safe will begin to look static. The world is all stocked up on unimaginative, pedestrian, generic photographs that anyone with a camera can make. There are billions of such images uploaded to social media platforms and other websites every day.
Your viewers, your friends, your family and your clients deserve better - and you can produce better - if you commit to producing better. If you are willing to do whatever it takes. It will take time. There will be disappointments and frustrations. But in the long haul, your images will improve; your eye will become more discerning. Your composition skills will mature. You will begin to produce some nice images. Nice comes before great; great comes before excellent; excellent comes before outstanding - and for a very rare few photographers, outstanding will give way to transcendent. If you truly love this art form, transcendent is your ultimate goal. Good enough is just not good enough.
"The Rules" are like a set of training wheels; you have to know when to use them and you have to know when it's time to cast them aside. You will see training wheels on the bikes at the local playground. There are none to be found in the Race Across America or the Tour de France.