First of all, it's good to know that there are very easy ways to discover keywords to better rank your videos. The autocomplete, for example: do a test on the YouTube search bar, and it will automatically suggest a more complete phrase.
The interesting thing is that these suggestions are based on the most searched words on YouTube, so evaluate if you can produce content about them. There may be a keyword giving soup to your company and you don't even know it!
Another tip is to take a look at the tags used by competitors or content producers that have successful videos on a subject that you want to rank. Since YouTube doesn't show publicly, you will have to spy on it. Just press the right mouse button and click on "View page source code", then Ctrl + F and search for keywords, which the tags appear.