A job aid is a great way to note the key concepts of a topic for later review. It is important to keep it short and to the point to be most effective and flexible.
I try to limit the job aid to a single page and to use a text font large enough to be seen if displayed on a small mobile phone screen. This allows me to reference the job aid while I am out and about, at the moment of need.
If more than one page is needed for the important content, I break up the material based on the topic so that each page can stand on its own as a reference tool. When multiple pages are required, focus on a readable font for a mobile device and then let the PDF reader swipe through the pages as needed.
Take a few minutes to create a short job aid and it will pay off long-term as you are able to reference this material any time, from anywhere, at the moment of need.