Students who arrive punctually have a small exercise book: like the old spellings books from primary school. When they arrive, the starter challenge is on the board and they get going on it independently. When the majority of the class are nearly settled, I put the mark screen up and they self mark their work. We then get on with the lesson. The students who arrive promptly and ready to work find it valuable to recap old work and theories and I now have more students arriving promptly, because they don't want to miss out.
Here are the first 6 Starter Challenges
Here are the first 6 Starter Challenges