To teach a challenging yoga pose think about comforting students, making them feel grounded, and then sparking their curiosity.
If possible ask students to begin in a position that is relaxing, like an easy seat. This is a chance to explain what will happen before demo-ing. Giving students an opportunity to relax their bodies before starting sets a calm tone for class. Avoiding anything funky in the beginning might make students feel less in the spotlight for what they are about to try. Your tone of the instructions, both spoken word and sound of voice, should be equally encouraging as well as casual.
The instructor should then demo and cue each step in clear view. Move to where students have the best angle to see you in the room. Remember to do the pose on the opposite side as the class if you are mirroring the students by facing them. You may not necessarily pause class to have a session on the pose however it would benefit the students if you do. Go one round with the demo and cues, then do it together. Keep giving instructions while the class takes each step at a time as a whole.
Teach to the mid-line – so don’t invert or take the most challenging pose right off the bat. Once in the most accessible variation of the pose, then give options to deepen or modify. Be sure to take a variation or offer blocks so most students can achieve some variation in class. Two examples are to have your foot by your ankle in Tree (vrksasana) or to keep your toes on the ground in Crow (bakasana/kakasana). Seeing the instructor take these modifications can also be encouraging for students who need these adjustments.
In summary, there are 4 main things to remember. Setting a positive tone before starting, showing the students the pose, talking everyone through it, then offering modifications. Encouraging students that failure is a good thing, too, can pique students to cross the mental threshold of a challenging yoga pose.