I used a spreadsheet to take notes and keep track of my attempts. If I'm getting something wrong multiple times, clearly I didn't learn from my mistakes. I make note of topics I got wrong or was uncertain about. After my final pass through Destroyer, I consolidated my notes into a document file and deleted stuff that I knew very well now. I would then focus my review on stuff that I still found somewhat tricky. This might involve Googling various explanations from multiple sources to get a clear understanding of the topic. For equations, I noted anything I couldn't confidently recite from memory or derive on the fly.
After the 2nd attempt, I started being able to answer questions but based on rote memorization of the question and answer which clearly isn't a good thing. So to make sure I understand the actual material, I mentally explain every answer choice and also anything even remotely related. In this manner, each question is like a cram review session for me. For example, if a problem was asking about the function of Immunoglobin D, I would explain that mentally, then I would also mentally explain the other immunoglobins. Then I would further expand on that and remind myself that IgA or immunoglobulin "apocrine" as I remember it is secreted in milk which confers passive immunity which is immunity gained by transfer of antibodies which is in contrast to active immunity. Active immunity involves the body responding to pathogens and developing its own antibodies. And so on... Point is, I get a crazy amount of review done this way. Yes, it takes longer than normal but I find it to be a worthwhile strategy to constantly test my own memory.