Basically you can manipulate all the items in the design and add 'items' to the design. For instance, we use automation to draw a border around the design and fill in some fields like the project it belongs to, the date and that kind of stuff. Also we create drawing layers with automation for documentation purposes.
I also use automation as a little tool to quickly "correct" things. Let me give you an example.
All our components have two placement outline. One that is identical to the assembly outline, the height of this outline is set to the actual component height.
The second outline is used as a placement outline, Everything that is part of that component is inside that outline. The height of that outline is set to 0.
When placing a part under an other part (shieding ed...) The placement check will issue an error because of the placement outline with height=0. The checks
cannot handle a height=0. So a litte scripting is done to modify all the placement outline with height=0 to height =0.01. Now the checks run as you expect.
Hope this gives you an idea.