Change the default administrator password! It’s a slap-your-forehead mistake we see time and time again. Just because something’s super simple doesn’t mean it’s not super important.
Big picture, any IoT security problem needs to be addressed with a two-pronged approach. First, a lot of security issues are actually caused by accident, so teaching the members of your organization how to be responsible with their devices is step one. The second prong is to make sure that you’re always staying current with the firmware and implementing software updates. As a corollary, you want to do your research on what security measures are available for your specific device.