I've taught many people how to consume OSINT, but never about creating OSINT. OSINT is information that is publicly available, and flying a drone in the US, with a some exceptions (restricted/controlled airspaces/open air assemblies) can be done without authorization/permission.

In this video, I create an orthomosaic of a burnt down motel in my local area. The tools I used:

DJI Mini Drone: https://amzn.to/3HcAVgo
DroneLink for Map Planning: https://www.dronelink.com
WebODM for image processing: https://www.opendronemap.org/webodm/
Maps Made Easy (Secondary mapping and processing tool): https://www.mapsmadeeasy.com/