What I do is to run the exiftool to strip all the metadata from the image. Next, I check if there are any identifying details in the image like landmarks or background details (e.g. stuff on my whiteboard). And finally I check for the unwanted reflections or for the setup that could be recognised outside the community I share the photo with. Last but not least, I never share a photo in more than one place.
Print it out, scan it. Screenshot again. Post it from behind 7 proxies