The thing with a “main character”, is that the reader see the story/world from that characters point of view – we can often read the characters thoughts and feelings more than other characters in the story. You can also use the perspective to increase this “effect”.
You can use the eye-level to display the world seen from the main character. Look at the two pictures above, the characters have the same size on both pictures – the only difference I’ve made is to switch eye-level. And by just doing this, we switch between the adult and the kids point of view – even though they both look at the same thing.
So, when you are doing a perspective, FIRST decide the eye-level and after that start placing out all those annoying guidelines.