Good tips above. Google Alerts is what I always start with since it's free, so at a minimum have this set up and get into a habit of checking the alerts.
If your company or team has budget, you can look into competitive intelligence services such as https://www.crayon.co/ or https://klue.com/. I haven't used either one before so I can't speak more to it, but it's something I can imagine being quite helpful.