Make a Cheat Sheet

No, were not saying your teen should smuggle in bits of paper into the exam. A Cheat Sheet is something your teen should prepare in the last few days before each exam.
Its purpose is to help your teen remember things that are hard to remember. Content such as facts, important peoples names, place names, subject specific terminology, formulas, processes all of those fun things.
Most students find it easier to remember more conceptual content well, once they understand it that is. But there are parts in most subjects that require students to just know something.
Unfortunately, these things can usually only be rote learned, rather than inherently understood.
For example, as part of writing a history essay, your teen will need to back up what they say with evidence such as peoples and place names, dates, etc.