Used to have vocab tests in my AP English class Junior year of highschool. The vocab tests were weird because they used to build upon each other, so the first month it was like 40 words, then 60 the following month, then 80 etc. As expected, sometimes I would forget like 2 of the words from the first month, and then like 5 from the new month and it got worse as the semester went on.

So there were like 20 or so terms by the final (Out of total like 120 words) that I didn't know. So I came into class very early in the morning of the final, and in my 'unassigned seat' I wrote down all of the terms that I didn't know very lightly directly on the desk. We had these old and crummy seats that were beige in color, so if you wrote lightly on the desk it was almost impossible to tell from a distance what you wrote.

So during the final, I grabbed my seat, went through the words that I didn't know by squinting at my desk until I found all the words and just smudged them off after I got them.

Pretty sure I got an A on the final and an A in the class because of that method.