A reader asked me yesterday whether it would be easier to draw a sketch of the site I am casing on a piece of paper instead of using an iPhone or iPad.
The truth is that it is. And I've been doing this since I can remember. Here's an example:
I still prefer this method to the digital option, however in the past year I found myself performing overt recon (inside the target prior to the actual op) and drawing on a notepad would be a bit strange, it would draw attention, whereas someone with a suit typing on a smartphone looks like something that is perfectly normal nowadays.
Anyway, I usually lay out the guards, doors, pathways, elevators and other features and I measure the distances from the entrances to my target. I pay attention to security devices such as cameras, locations whre a badge (ID card) is needed, etc.