Useful practice for creative endeavours not limited to writing, I think.

[..] write about three things: where they’re stuck, what they plan to achieve next time, and what they were thinking about when they stopped writing. [..] As a writer, your per-minute productivity hinges on how fast you can ascend to the Skyway of Satisfaction. As simple as it is, capturing the view from the top is a fast-pass through the Mountain of Agony and onto the Skyway of Satisfaction the next time you write.