You do need to have an idea of what you want to write, whether it be articles, stories, a novel, or something else. Again, for instance, if your main goal is to finish a novel, then think about what your weaknesses are, as well as your strengths. You can follow this pattern regardless if your goal is x number of articles, or a short story, or a novel. Every book has its own demands. And writers learn to change their strategies depending on the demands of the current project.
Some writers are more productive with a deadline looming.
The writing plans of others are bound by the other work they do. The key is, when necssary, to loosen up and try other patterns of working so you aren't fighting yourself. Writer A doesn't have a lot of professional credits. As I know to my own regret, this is especially true with a series, where it's vital for the poor author laboring under the weight of seemingly infinite sub-plots and a monstrous mob of clamoring characters to keep track of everything that's going on as well as the main character's eye color. It depends on the person, your pattern of writing, and your project.