I used to make decent money from betting but moved away to safer stuff
Lemme tell you what I used to do and maybe that will help you in some way.
1. Pick some interesting matches (preferably top tier teams)
2. Analyse them BEFORE you see the odds, and try to make your own odds
3. Look at the odds on the betting sites that you used, and if the odds are better than the ones you just made up, then bet on it.
Na'Vi vs FaZe, based on the recent results and the map pool I consider FaZe a favorite, maybe around 1.6 for FaZe and 2.1 for Na'Vi -> The odds on a betting site were 1.75 for FaZe and 1.9 for Na'Vi, so I chose to bet on FaZe
Not sure if helpful but that worked great for me back in the day