I often start off a lesson with a class by simply saying at the beginning of the class 'What do you remember from the last English lesson?' Now, perhaps that lesson was one or two days ago, perhaps it was last week, it may have been even two weeks ago, it doesn't matter. So, individually they have to stop and try to recall any words or phrases at all that they may remember.
Usually, they say 'Oh Sir, I don't remember', and you can say, 'Well, look, just for a few minutes I'm going to ask you to try and remember and write something down. I want two words or phrases from everybody in the class, it doesn't matter what it is, even if it's something very, very simple.' And, if really necessary, remind them of the topic of the lesson.
It's amazing what in fact they can remember. Next ask a few people to come out and write on the blackboard what they can remember. When you have your blackboard full of words and phrases, stop the class and ask everybody to look at it and check if the spellings are right and to remember the meanings or to try to use in an example sentence.
The final stage of using the board means there is a sense of shared memory in the class and a clear focus for the activity.