Determine the goals that you have for your students. When writing a lesson plan, both the goals and objectives of your lesson will be included in the document. The goals differ from the objectives because they are used to help you articulate what you want to accomplish and allow you to plan how you will teach the lesson.
Use the goals you set for yourself to determine what you expect from your students. These expectations will become your learning outcomes. Where a goal is focused on what you as the teacher will do to help your students, the objective is focused on what your students will be able to do after the lesson is over.
Provide measurable outcomes. Your objectives should always be measurable, meaning that you can use some tool to accurately determine whether or not your students meet your goals and objectives. For example, a measurable objective might be to have students be able to read one 10-page book to the class during a class period. You would then be able to test your students' ability to read a 10-page book to the class.
Communicate with other teachers who have taught the class before you to determine what their goals and objectives were. This will be especially helpful if you are having a difficult time coming up with objectives for a particular lesson. It can also be helpful if you are trying to discern whether or not an objective is reachable for students.
Write the objectives out with your lesson plan. You will need to refer back to your objectives throughout your lesson to ensure that you are staying on track to help your students reach their objectives. If the lesson spans over the course of multiple class periods, consider having pop quizzes to determine how close your students are to meeting their objectives and adjust the objectives accordingly.