just finished a one-shot I have been working on for the past couple of weeks, on and off. had the os outlined on my notion, which made the entire writing process surprisingly a lot smoother, and easier in the sense that I could walk away and come back knowing what direction to go. Whereas, when I'm writing spontaneously, and strictly mood-driven, the story tends to split off into a million little directions with no conclusion.
I guess this is why many authors swear by story outlines. It keeps them on schedule. On topic. It allows enough room for flexibility in that you can elaborate and rewrite certain bits but does not let you stray too far.