Samantha Starmer outlines 4 key principles for structuring an effective presentation: 1) Start with yourself by identifying your goal and style, 2) Learn the environment including audience and time limits, 3) Build the structure by freeing your mind and remembering your goal, and 4) Leave time to adjust through rehearsal and ensuring your main point is clear. She provides tips for each principle such as scouting the space, keeping a narrative, and rehearsing more than expected to create a well-structured presentation.