The single best piece of advice I have for writers.

The first time I wrote a book based on a year of observation, I moved out of D.C. and into a bare-bones apartment a three-minute bike ride from the school I was writing about. It was 2001. It was a miserable year for me, personally. My father was in a motorcycle accident (he recovered), my grandmother died, I got dumped by a guy I loved and one I just sort of liked, and September 11 layered onto all of that to leave me utterly disconsolate.

I had no life, unless by “life” you mean following 12-year-olds to the roller rink on Friday nights and actually feeling jealous they had partners to couples-skate with. (I know! Embarrassing! But if you have ever been depressed, you know what I mean.) In a way, this physical and emotional isolation was a gift when it came to my work. It was too painful to focus on myself, so I focused 100 percent on my middle schoolers. Aside from online Scrabble, I had no distractions. I had all the time in the world to accomplish all of my friend Hank’s “13 Questions to Gauge How Well You Know a Source,” including the one where you see your subject go to sleep and wake up.

Most important, I had nothing better to do every evening than to transcribe my notes from the notepad to the computer. From William Strunk Jr. I learned to omit needless words. From David Finkel, an early mentor, I learned not to say the same thing twice, even (and especially) if it’s in two different ways. And from Margaret Mead I got the best possible advice for a narrative journalist: write up your notes as soon as possible.

Whether you are writing a book or a weekender, when you unload your notebook on the day of your reporting, what’s written on the pad (or even what you capture on tape, not my preferred method) is just a teaser for your brain, which fills in the copious blanks of every scene and every thought. This is time-consuming—I spent three or four hours a night on this early in the year, less time later—but well worth it. I could IM or call my subjects, asking, “What were you thinking when such-and-such happened?” and of course they would remember, because it was a few hours ago. A word in my notebook became a paragraph in my computer file. A quote became an entire anecdote. From the scribbles on one page I managed to write lengthy scenes off the top of my head that needed only a bit of polishing, months later, to be bookworthy copy. When summer came and I sat down to write a draft, I did it in five weeks.

Contrast that to how I approached my second book, four years later. I was commuting from Baltimore to Annapolis, 45 minutes to an hour away. I was committed to the project but also happily distracted by my wedding, my honeymoon, my life. A friend of mine, who is something of a big-deal journalist, was doing her own narrative project at the same time. She went months without unloading her notebooks! So why couldn’t I?

I was not that lax; I would wait days, or at most weeks. I knew it was a horrible idea. I still had tons of material on my notebook pages, I just didn’t always remember why it was important, or what happened in the background that I wasn’t able to write down, or even sometimes what that awful handwriting meant—things I would easily have been able to retrieve if my memory was fresh. When I sat down to write a draft, I had strong, solid material, but I knew I could have had so much more to choose from had I been more disciplined about transcription. Writing the draft of that book took five months.

I never understand people who say they have no regrets. I regret drinking too much tequila and French 75’s the night before I flew to Mexico in 1999. I regret about 60 percent of my clothing purchases. And I regret being lazy about my notes. Readers wouldn’t be able to tell the difference from the first book to the second. And I don’t know what is missing—just that something must be.