If you know that my habits will bother you, select two or three individuals toward whom you will direct your comments and avoid looking at me. I will not take this decision personally and I may not even notice. Notes will allow me to provide you with feedback and to make a more attribute-based assessment of your presentation. I also wish to avoid smiling and nodding at some individuals but frowning and eye-rolling at other individuals, especially if those feedback cues derive from factors other than your presentation. I am most interested in your thorough treatment of the topic, organization and presentation, and readiness to answer questions.
Someone inevitably asks how the presentation is weighted.