Polarities when creating charters

When you charter your tests, see what happens when you include polarities explicitly in your mission.  For example, look at testing vs. touring; or feature vs. feature; etc… After you've done this for a few charters, note how it changes your testing. Does it help you focus? Is it distracting? I find that doing this sometimes helps me better focus when testing. Especially if I'm chartering a shorter charter (20-30 minutes).