Elena,
I think there can never be enough time devoted to practice and review, so I gear my back-upplans towards that objective. This can be dicussion (small group, whole class, student-led, instructor led), pair share, white board, or flip chart. These activities can be planned to fit the time available or remaining. A good back up plan is one where the students may not even be aware that an unplanned activity is being used.
Barry Westling
