Fitting is as individual as bodies are. Generalizing on fit and pattern corrections without more specific details is not only irresponsible, but it confusing to people that have little experience and are trying to understand the correct way to fix patterns.
Is the garment tight because the persons back is too wide, which would pull on the front?
Is it because the bust projection is larger than the standard C cup?
Is it because the pattern used is too small for the person's body
Is the depth of the armholes at side seams wide enough to accommodate a person's wider body?
Are the armholes or the sleeve too scooped out impeding movement?
Is the front neckline too wide, and the back neckline not wide enough?
There are many, many reasons why a correction maybe needed, and there are as many options to change a pattern.
Understanding individual body shapes, the body stance, what styles will look better on particular body shape, how to enhance certain areas of the body to look taller, thinner, wider would be much better idea to help people in understand how pattern shapes relate to the body shape