Unit testing best practices?

I'm spending 30%-40% of development time on writing unit-tests.

What are some of the best unit-testing practices you know?

I read that:

• Tests should have a minimal scope
• Tests should act as documentation
• Tests should be deterministic
• Tests should be integrated into CI/CD
• You should work with mocks
• You should leverage tooling to determine code coverage

Any other best practices?