I’m very curious what ENTOS training material is going to be about.

Phase 1: Show your students this video about self-esteem before the start of the lesson: this is an introduction to what self-esteem is and what its importance is, and it introduces the activity of the headstand as an exercise that helps the students develop it.

Phase 2: This exercise has to be done in pairs: one student does the exercise of the headstand, and the other takes care of him/her. This second student is also called “the spotter”. The spotter is a fundamental role in safely executing some yoga positions, as he guarantees the safety of the other person. He is also in charge of observing and guiding the execution of the yoga position, and the bigger the risk of the position is, the bigger his importance is. 

Every student can be the spotter, but it is recommended to have 2 spotters when the person executing the yoga position is much taller or weighs more. It is important to practice yoga playing also the role of the spotter, because it helps understand the technique and the functioning of yoga, and brings an enhancement of empathy; you can’t ask your spotter to pay attention if you didn’t pay attention when you were the spotter.

The position of the spotter is the Goddess Pose: start in a wide standing stance, and turn your toes out and your heels in, with your feet at about a 45-degree angle. Bend your knees in the same direction as your toes, and lower your hips down toward the height of your knees. Reach your arms out at shoulder height and bend your elbows so that your fingertips point skyward. Spread your fingertips wide and activate the muscles across your back.

The spotter must use this pose, as it ensures safety throughout all the exercises for both himself and the other student.
Since this exercise is intended to be realized in pairs, there are two levels of learning:

1: the student doing the headstand observes himself and reflects on his movements to correct and adjust them.
2: the student-spotter observes the movements of the other student of the pair and supports him in the activity (with the support of the explanations of the teacher); this way, he can both correct the mistakes of the other and reflect on his own mistakes when doing the exercise, improving his technique.

To do the headstand, you can show the students this video first, so that they can see all the sequence of movements:

And then you can guide them with these instructions: 
1- Get on your hands and knees with your wrists under your shoulders and your knees under your hips.
2 - Bring your forearms to the floor, keeping your elbows directly under your shoulders.
3 - Clasp each hand around the opposite elbow. Adjust as needed to ensure your elbows are the right distance apart.
4 - Release your hands from your elbows.
5 - Clasp your hands together on the floor, interlacing your fingers.
6 - Place the crown of your head on the floor. The very top of your head should be down—neither too far forward nor back. The back of your head will rest at the bases of your thumbs rather than your hands holding your skull.
7 - Lift your hips and straighten your legs. Carefully walk your feet toward your head until your hips are as close to over your shoulders as possible.

The headstand is a useful exercise to strengthen the upper body and the spine; in particular, the abdominal strength is much improved, as well as the stability and balance of the person.

Realizing this exercise requires previous work on self-knowledge; only by mastering it, the student can know his body enough to execute a headstand. Being able to do this exercise results in an enhancement of self-esteem and self-confidence, considering the difficulty of the activity.