One of the hardest bad teacher habits to break is learning not to repeat yourself when you give whole group directions. Part of the reason that it is so hard to break this habit is that we want to help students. It's simply impossible to refuse a student's request for help. Another reason is that no one has taught students to listen carefully and so repeating the directions several times may help students stay on track.
It’s one thing to clarify information or explain directions; it’s another to have to repeat yourself for students who are not in the habit of listening attentively. Don’t assume that your students are good listeners. Many have never been taught how to listen attentively. It's up to you to help students learn when and how to focus their attention when their teacher is talking to them.
To begin to break this time-consuming and frustrating habit, involve your students in the project. Tell then that you are going to help them with their listening skills and explain how that you want them to listen attentively. No talking. Eyes on you. No rustling papers. Create the procedure that you want for your students to use as they listen to you and take the time to carefully teach it to your students.
Set the stage by moving to an area of the room where all students can see and hear you. Call for attention and wait patiently. Remind students that they will be working on their listening skills and that they are to listen carefully since you do not want to waste class time by having to repeat yourself.
Practice with your students if necessary. Make it a shared endeavor and a pleasant way to work out a classroom problem together. With a bit of effort, this can become a part of the culture of your classroom, and you will find yourself not having to repeat directions or other information endlessly.