Along the lines of redressing the reading-listening imbalance, I’m doing the following. I took the Japanese text with which I’m most familiar—the first chapter of Harry Potter and the Philosopher’s Stone—and turned it into a word document. Then, I put each sentence on a new line. And finally I started highlighting.
So as to focus on structure, I read and decide whether each sentence’s meaning lies within my grasp. I guess I’m searching for i+1 sentences (see Krashen).
I have no ultimate aim, but it’s fun to highlight such sentences, or the longest phrases of more challenging sentences.