>>208203
Any serious cartoonist will tell you that the most important thing is fundamentals. Why are fundamentals important? It isn't so you can slavishly cleave to them with no deviation, but so you can deviate from them effectively.
Look at Yotsuba: Yotsuba's head is completely disproportionate. But in general, everything makes sense. Even Yotsuba herself is distorted in such a way that she still gives off a sense of reality and weight, rather than just being a figure on a page. This, despite her ginormous head.
As for other comics, even basic shapes need to conform to certain guidelines. If you look through manga or Western cartoons or Western comics, there are tons of styles that are complete distortion. The difference between good distortion and bad distortion is that good distortion is recognizably distorted from a solid foundation, whereas bad distortion is distortion that has nothing as a base.
Look at the Powerpuff Girls, look at Johnny Bravo, look at Dexter's Lab, for god's sake. They're distorted, so so so unrealistic, but they follow rigid, internally consistent rules, and although the proportions aren't realistic, they are distorted in such a way as to give a specific atmosphere, rather than just being distorted.
When you say that manga is different because other cartoons are made of more recognizably basic building block shapes, you're missing the overall. You're focusing on the details, you're focusing on the style, you're focusing on the icing of the cake. The key is the foundation, and if you have any sense at all, you'll KNOW when something has a good foundation and when it doesn't.