How do you (or do you not) camouflage an aircraft plant?

Oh Dark Thirty

Aircraft plants are strategic assets and camouflaging them is a necessity. Growing up in Maryland, I had long heard the stories of the failure to effectively camouflage the Martin Aircraft plant. They covered the whole plant, including its parking lots with netting. Sure, it made the plant invisible from the air but the adjacent river and railroad tracks formed an arrow pointing directly at it. 

Camouflage netting covering parking lot at the Martin Plant during WWII

Then came the winter snows collapsing the whole thing and trapping employees cars for months.

Boeing took a different approach. They constructed a town over their plant.

Looks like a nice place to live, doesn't it? Of course the "neighborhood" was kind of noisy.