Feedback really is one of the most important and fundamental aspect of teaching PE. The first step to giving effective feedback is knowing the types of feedback and even more important, knowing your students. By knowing your students, you can evaluate which feedback is going to be most effective for each individual. The first and most common type of feedback is positive feedback. This type of feedback focuses only on the correct things the student is doing. Then there's neutral feedback, which is more of going over what their doing and reminding them of any cues or key focuses being taught. Last there's negative feedback, which leaves out any positives and consists of pointing out and correcting what the student is doing wrong. Depending on your student, all of these types can be effective and even more effective when combined.
In my first lesson I noticed that I didn't give any feedback, general or individual. After watching myself teach I can easily see how giving feedback can greatly increase the effectiveness of the lesson and I now will be sure to incorporate feedback in all my lessons.