Apart from your own research and domain expertise, there are various ways you can sharpen your product sense further:
1) Get feedback directly from users
2) If your product offering is an online one, use tools like Hotjar to analyze user behaviour when using your product .
3) UX research or focus groups - ask testers or focus groups participants
If you see a gap in your product offering versus the way your users are consuming it, iterate and adapt.
Cheers!
Solopreneur Rocks