Knowing How Much to Include
It's tough to know how much to include in a new lesson. While you can gain some insight into timing through years of experience, even veteran teachers occasionally overplan or underprepare. If you have to choose, err on the side of overplanning. It is much easier to cut things out of a plan or continue it on the next day than to fill up twenty minutes.
With this said, your goal should be to always plan for about 10 minutes longer than you think you will need. Keep a stock of “mini-lessons” that you can pull out as needed in order to fill up any extra time you might have.
Effective Use of Cliffhangers
One technique that effective teachers employ is to use cliffhangers at the end of a day's lesson. When you are excited about your subject, your students will be as well. Leave the kids little hints to entice them; this excitement will carry over to the next day's lesson.
Cliffhangers can take many forms, including handouts, questions on the board, or brief discussions that leave questions unanswered until the next day. Keep the cliffhangers in mind as you create your lessons.