More progress in drawing...
Remember "quick draw?" This has evolved into a realization about drawing and "keeping the whole".
When drawing the figure, never draw body parts in isolation. In other words, never draw "an arm" or when drawing the face, never draw "the eyes" and then "the nose" and then "the mouth". Nope. Don't do it.
Every line you put down, every patch of value, every stroke should in one way or another connect and be related to all the strokes you already have drawn--whether through perception, invisible lines, directly, or whatever.
This is important. This means you can't draw a line or put down any mark without keeping all previous marks in your mind and connected on paper. It's this mental as well as physical connection between the "parts" that lends solidity, weight, mass, and "correctness" to a drawing. It's the real secret of keeping your proportions correct.
The human brain has a much easier time keeping track of 3D shape than it does keeping track of stray lines. A line is a good abstraction ... sometimes... for the edge of a plane, but a 3D shape represents life much better. So, when putting down a stroke... careful consideration must be made as to how it fits into the drawing. It's like putting a piece of a puzzle into place more than it is laying down some independent piece.
Every line must fit, every stroke must make sense in context with what you've already drawn. If you haven't drawn anything yet, this is the point where you must establish at least one stroke, and then feel out the initial form(s) in your mind. From there, it's all a puzzle-piece interlocking exercise... because no stroke can stand on its own if you want a harmonious and well-proportioned drawing.
So, while you're moving your pencil or pen or stylus, strive always to feel the connection to the "whole piece" rather than trying to make a good looking arm, or nose, or anything else.