Every team must do regular retros
Effective communication is the best indicator of any functional team.
The best practice for improving communication is doing it regularly.
And having a safe space for expressing your observations.
This safe space is a regular retrospective.
Do it with every team, do it every two weeks, do it for 30 minutes.
Accept awkward silence, accept that people say they have no topics.
Someone will eventually say something.
And this will matter.
And it will start a good discussion.