>>96406705
Watch some heist movies -- good ones. Pay attention to the crew, especially their roles and unique specialties. Take note of the heist itself. What are they stealing? Where are they stealing it from and from whom? What's the security like? How screwed are they if something goes wrong? When you're done, remove the specific details, leaving only the rough outline of the events. Then, fit those events into a Shadowrun framework. Which corporation are the runners going up against? What exactly are they stealing and from where? What's the security of the place like? (note that, when it come to Shadowrun, there are three levels of security: physical, magical and digital/the Matrix)

And, most importantly, what sort of trouble are the runners looking at if they manage to fuck up?

A map of the place they'll be infiltrating alongside notes regarding the above questions will be important. Make sure to note where things like cameras, drones, magical wards and other security measures are for future reference, as well as guards, their equipment and their patrols.