Ernest Hemingway advised to aways stop for the day while you still know what will happen next:

“The best way is always to stop when you are going good and when you know what will happen next. If you do that every day when you are writing a novel you will never be stuck.”

“I had learned already never to empty the well of my writing, but always to stop when there was still something there in the deep part of the well, and let it refill at night from the springs that fed it.”

I find this true of painting. If you can’t finish it immediately, always stop when you know what your next move will be. Then it is easier to step right back into the flow you were in before, and it is easy to get started again.

It probably holds valid for any creative endeavor! Give this a try in whatever you are working on. I find it enormously helpful, especially in long, many-stepped projects, or when there is inconsistent time in which to work.