Borders turned on in tables when not required, especially with unsightly borders. Anything that blinks, multiple things that blink Rainbow rules, especially if they blink. Under construction signs, especially if they represent little men or machines, and worse still if they are animated. Counters on pages - who cares. Too many pictures of meaningless awards on the first page.
Orphan pages, basically no way back.
No focal point on a page, or too many focal points on a page.