There's a related medium where I think similar advice applies, technical papers. At least for my field - computer vision / machine learning. You choose a cool,

There's a related medium where I think similar advice applies, technical papers. At least for my field - computer vision / machine learning. You choose a cool, hopefully self-explanatory, figure to feature prominently in the first page. Something that will grab the attention of someone flipping through pdfs and get them hooked. In computer vision you can usually find something visually appealing, like a 3D reconstruction, or an image with highlighted object detections. If nothing else, you can go with a plot showing how much better your method is compared to a baseline, but that's probably less engaging for people who aren't super familiar with how meaningful the numbers are.