In my book, I show Japanese readers how to make mistakes freely—how to accept and make use of them. So why not apply that advice in my own case?
And so I made some adjustments. Based on the results, I continued adjusting.
For instance, I shifted my focus from single words to phrases to sentences. I moved from short-term to long-term memorization. I adopted a spaced repetition system, discarded it for another, and then finally just collected kanji in context.