Ask other members of your project team to pair with you from time to time when you test. It can be a programmer, another tester, a customer or business analyst, or even someone from operations. You'll be surprised with what type of conversations take place following such sessions.

Ask a programmer you work with if you can pair when they start writing unit tests. If they are doing TDD, ask if you can sit with them for an entire programming session. You'd be surprised how much valuable discussion can come out of even one such session.