I'm not going to sugarcoat it — I bombed the CER certification the first two times and almost gave up entirely. First attempt I went in thinking my field experience would carry me through without much prep. Big mistake. Scored a 61 when I needed a 75. Second time I studied but kind of all over the place, no real structure. Another fail, 69 that time.
What finally clicked on attempt three was being ruthless about where I was actually weak. I used a CER practice test every single week for six weeks straight and tracked which domains kept biting me. Turns out my conceptual knowledge was fine but I was consistently misreading scenario-based questions. The study guide I'd been using didn't have nearly enough of those, so I switched to one that was heavier on application questions.
Passed with an 81 last month. Happy to share what I used or answer questions if anyone's grinding through this right now. The exam tips that helped most were honestly more about test strategy than content knowledge at that point.