With my students I always start by giving them my phone number. I tell them to let me know if they have a problem getting to class. The last thing I want is for them to feel like if they are 5-10 minutes late. they should not even show up. I don't wait for them to start teaching, but I feel like this understanding keeps them coming and motivated. I teach math, and they already feel intimidated from the get go. They are responsible for catching up, and I find they always do.
