I'm sure you've heard that planning is everything in creating art and illustration. You have to know your goal and what the client wants and who your audience is. To satisfy all those demands a plan can be the easiest way to achieve them. But there are other ways of creating art that are less structured and linear.
Take for example how, Giant Robot store owner & publisher, Eric Nakamura and, artist and illustrator, Saelee Oh decided to make a stop motion animation. They had a few ideas of what to do to start, but nothing was completely planned. They said it was really organic how it unfolded and they were surprised how fun and quick it was to make it. If you click on this link, it will take you to an interview with them where they talk about their process.
I found it inspiring how it was more "play", as they put it, than anything else. Through experimentation, it came to life. It ended up being a cute little underwater animation created with cut paper. I'd say they proved that sometimes chucking the plan or not having one to begin with can be the best way to make art. That will make me remember to go with the flow and have fun.