"To Ernest Hemingway, writers are like wells: "The important thing is to have good water in the well," he told the Paris Review, "and it is better to take a regular amount out than to pump the well dry and wait for it to refill."
In this way, Hemingway coined the phrase leaving water in the well: instead of spending all your creative juices all at once, you leave a little bit of inspiration so that you can return to the same momentum that you left it with. Hemingway, whose habits of badass productivity we've talked about before, said to never stop writing without knowing how you are going to start again, to, in other words, never end a day's work without knowing how you are going to start the next day.
But why does this help a workflow work so well? Leaving a task with an intention of how you'll resume it is the compositional equivalent to packing your gym bag the night before--you reduce the friction of getting back into writing your novel, designing your webpage, or building that game-changing presentation deck, thus making it easier to do the difficult, deep work and giving you one less reason to procrastinate."
As noted above, these are points to consider not only for writers--but for anyone whose work requires a constant reservoir of creativity.