I 'll show you how to make it easy.
When i'm assigned any jobs, it's mostly in graphic & rendering.

Ang Mo Kio, Singapore
First of all, Understand it.
I have to know about what the drawing wants to say to the people. This is the most important because drawing's mission is media. It has to convey the right information to people. For example, rendering of AMK Elevation, Its mission is to show overall appearance of color and materials. When I already known, I can proceed to the next step.
Second, Graphic/Rendering/Compositioning.
I define each materials by layers, some materials was separated for few layers or more if it need to be shown in differenc depth. For glass span, I render what should arise behind the glass and create new transperance blue-glass layer on top. Then, you can see the effect of glass to the inside function. And don't forget the happiness environment, trees, cars, people enjoy shopping, kids, shade, shadow etc,.
Third, Prepare for revision.
My boss, khun Bak, he always gives me pretty good comments, so I can't away from the revision. For the complicated layered drawing, I suggest to clear the unusable layer, delete them or merge together. It can help alot when making revision.

Graphic/Rendering/Compositioning
FINISH YO!YO! (^_^)
easy, right...