The exams that require no thinking or understanding but lots of memorizing - of lists, dates, names, messy formulas, etc. – without any lasting usefulness deserve to be cheated on. These are incidentally the easiest kind of exams to be handled by cheating. One should not push his luck though – if you are unsure about how to cheat on your exam properly and if the punishment is harsh, you must stay honest.
The cheating aid should be easy to read from. One has to make use of the limited number of things that are allowed at the exam. For example, when looking sideways under a shallow angle into the reflected light on a transparent acrylic ruler (a green-colored kind works best) the light reflection makes those nearly-invisible engravings to stand out. The teacher looming over you, watching you fruitlessly as you are calmly copying down the whole thing. There are stories about people with thick-rimmed glasses that had their exam notes written on the inside of their glasses. Elaborate contraptions have been made but as always one good simple idea works best.
Reserve few quiet evenings well in advance of the exam - the writing requires organized and condensed information and carefull work. After having prepared good crib notes with a great effort, sometimes one doesn’t need to use them because regrettably, the knowledge of the subject was somehow acquired during the cheat writing.
Do not involve others in your score-improving efforts. You are doing it for yourself and for the good grades that you deserve, for the challenge of defeating the oppressor. A fight against the system requires a discipline; the urge to brag about your exploits must be restrained. There is always some reckless freeloader, righteous killjoy and envious churl who would like to spoil it for you and everyone else.
A confiscated cheating device is not a proof of cheating, only the proof of a temporary intent at most. (Perhaps you had it with you but at the last moment you decided against using it because you realized it was a wrong thing to do - a man gotta listen to his conscience.) A confession of guilt will only get you expelled: Unless you were caught in the act and unless they have it on a video, it is hard to prove conclusively that you cheated. So don’t make it easier.
In early grades of the elementary school, we were sometimes asked to sing cheerful songs about the virtues of hard work. Even at that young age, I marveled whether a phrase “The hard work is a source of all progress” was a sound idea. I came to a conclusion that, in fact, laziness has been a source of all progress. Without the constructive and well-reasoned laziness, a man would be still tilling the land with a pointed stick.