With each step-by-step I try to come up with a guide rule that you might find helpful when drawing or when trying to decide why you don't like a drawing.
Most Important Rule -Take chances! If you want to experiment or think something will improve the drawing - Break the rules! If you are wrong, there are always other drawings. Either way, you'll have learned something.
In a crowded drawing, have more objects, less detail and less complexity. In a open drawing have fewer objects, more detail and more complexity.
Use Textures Step-by-Step
If you don't feel your drawing is working, or dislike a finished piece, look at the composition of your various sections.