Students who lose the planner are required to replace it. Teachers write assignments on the chalkboard or overhead transparency and explain the assignment orally. This only takes a few minutes at the beginning or end of class. Students should write down the homework even if they finish it in class. It is the student's responsibility to ask the teacher for this.
Parents check and initial the planner at home.
Make sure it is something that they can do independently, and insist on complete silence. For short term planning, remove the notes, and write a more detailed plan in the lesson book. Refer back to these notes when planning the next year. Model long term project planning for your students. If you have 2 or more sections of a class, even if they are not at the exact same lesson plan, run enough copies of material for all sections so that you will have copies when you need them.