I'm too much of a coward to cheat. Once my friend convinced me to try something we saw on the Internet. It's basically printing the periodic table in a small font and and sticking it on a water bottle. She was supposed to give it to me when she's done but I chickened out and ended up failing the test instead of cheating.
It looked like this

OMG all the talk in here of taking phones and coffee into exams.

Here in the UK, you're only allowed basic stationary and a clear water bottle. You couldn't even dream of cheating here without getting caught or disqualified, especially at High School/College level.