Create a reading corner. Arrange a couple of bookshelves in the corner, and stock them with books for your students to read. Put a large area rug in this corner, for students to sit on and read, or listen to you read them stories.
Bring in a couch, beach chairs, beanbag chairs or any other special type of furniture for students to sit on. Put these in the reading area of your classroom, and reward students with good behavior with the privilege of sitting there. This will motivate your students to be on their best behavior.
Hang fishing line and eye hooks from the corners of your room to display your students' work. You can still use bulletin board space for this if you choose, but the fishing line will allow you to display even more.
Change decorations based upon the lesson plans you are teaching. For example, if you are teaching about the ocean, hang fish decorations around the room, place a fishing net in the corner and line some toy boats on the windowsill. This will make learning exciting for the students, and help them to put your lessons in context.
Decorate based on upcoming holidays. Make the room festive during the Halloween season by placing pumpkins around the room, put hearts all over the walls near Valentine's day and put shamrocks up in March for St.Patrick's Day.