This shows about 12 minutes of drawing compressed down to 90 seconds. Done in Photoshop but the principle is no different then working in my sketchbook.
The most important rule is to start out as general as possible. I start with a really rough circle just to lay out a starting shape/size. The circle becomes obsolete in no time but it served it's purpose. Then it's the big shapes, in this case the face and the hair. Next a quick center line and a nose, mouth and eye line. From there building it in with short geometric lines always following the general to specific rule. I do all this work with lighter lines and a softer touch so they are easy to remove as more solid lines are placed (particularly when working on paper).
People like my crosshatching finish work but this is the most important step to the drawing, getting the structure correct. Feeling confident with your foundation allows you to be bold with your polish work.
Hope that helps. Feel free to ask any questions and look out for more steps soon.