This is going to sound strange but here goes: When someone gets up to speak - the Rabbi in shul, someone at a simcha etc. etc. LOOK AT HIM!!!!!!!!!!!!!!!!!!
If you are makpid on shmiras einayim and it is a woman speaking - don't go in the first place...
But if it is a man speaking - stare at him! Look INTENTLY.
Why? B/c by golly it is offensive or hurtful or disconcerting to a person when he is speaking to YOU and your gaze is focused elsewhere. If you went out on a date and the other person didn't look at you - would there be a second date?
This not-looking-at-the-speaker happens a LOT. Some people look into a sefer. Hashem wants a person to learn when it is offensive to another human being?? People, even "chashuv" people, do it.
Others close their eyes. Is THAT Kavod Habriyos? A person wants to share thoughts of Torah and people take advantage of the opportunity to catch up on their rest.
Some look around. What is so interesting about what is happening elsewhere??
If it isn't Shabbos or Yom Tov then people are busy with their electronic toys. I was once sitting in the back of a shul in Manhattan and the Rabbi was teaching Mishnayos between Mincha and Maariv. About EVERY PERSON in shul was playing with his toy. [Not me - I don't own that toy!!!]
Some people have their back to the speaker. They can't turn in his direction? How would YOU feel if you were talking to someone and he insists on turning his back to you as you talk.
When the כרובים in the Kodesh Kodashim had their backs turned to each other that meant that Hashem was displeased with us. When they were looking at each other in the face that meant that Hashem was happy with us. It is a show of love and connection.
Great chesed. You can do it. You want to be למהדרין??? Move your seat up close and stare intently with your head forward. Show him with your facial expressions that you are absorbing his message.