Every drawing you undertake has a hierarchy. There are the general elements. And there are the fine details.
Matthew Frederick recommends laying out the entire drawing to start.
By making use of:
Light guide lines.
These techniques will help ensure the proportions and placement of shapes are accurate.
After that hit the details. But don’t over indulge in one place:
When you achieve some success at this schematic level, move to the next level of detail. If you find yourself focusing on details in a specific area of the drawing, indulge briefly, then move to other areas of the drawing.Matthew Frederick