Writing it down is about taking what's in someone's head and putting it on paper. It's important to make sure that the answers exist-and they exist because someone can pick them up later.

Creating good product habits, like thorough documentation, can seem menial when you're just two people in a room. But as you grow and scale, spending an extra 5-10 minutes to clearly communicate what's in your head is the only way you can scale. Documentation is a reusable asset, and one that accrues in value and in quantity over time.

In order to be good at building products, you have to be able to break apart the problems behind them and approach these problems from a multitude of different angles. What enables continuous improvement is the ability to build off of the universal first step, and the second, and the third, synchronously as a team. Documentation provides the steps, and habit makes it come alive.

Here are a few of methods to get documentation right:

• Get outside the product team. To make sure your product team is on the same page, Ben Horowitz advises getting "someone outside the product team to ask 5 different people in engineering, QA, and doc what their product is supposed to do and why and get the same answer."
• Make someone else do it. The stress test for whether or not a piece of documentation is good enough to pass the bar is to have someone else read what you've written and try to apply it. If someone else can't repeat the process that you've written down, you've written it down wrong.
• If it's not on paper, it doesn't exist. Distributed knowledge on product processes throws a wrench in the gears-they may as well not exist. In order to reinforce the importance of documentation for your team, treat them as if they don't exist. If you only give credit for something that's written down, chances are high that your team will write it down.