Oh man where do I even start, I can go on this topic for pretty long. I'll try not to deviate too much. Feel free to hit me up on discord if you want to get into a more extensive discussion (I love the topic), or we can follow up here if you want to learn more.
About 2 years back (2022), I decided to take a serious shot at it, and basically put down in writing almost everything I had in mind which I had refining in my mind for years. So I had a very clear idea of the overall story, the characters, and the main story beats. I discussed the whole thing with my wife, and even started plans to change my work schedule to dedicate time for this project. I wrote some key concepts to serve for the first few chapters, and restructured a lot of the story to streamline it.
1) The first thing I did was buy my tablet and try to figure out what I would need, both in material, time and designs (environment, characters and so on). I researched about software, how things got published (webtoon, pixiv, etc), and so on. First few weeks was all about research, learning to use the tablet, and focusing on creating a one shot to serve as testing grounds.
2) Once I settled on the one shot, I designed the characters, wrote the story and since I had no idea what I was doing, jumped straight to doing the one shot with Krita. No draft, no actual structure, just winging it, learning as I went along.
3) Once I finished the one shot (which by today work looks sort of crappy), I shared it, got some feedback, got excited, and dived into telling the bigger story as I did chapters 1 and 2. At this point I was still winging the whole thing. The first two chapters lack refinement and structure, but I learned a lot doing them.
4) After those two first chapters, I realized I needed to refine my pipeline more. So I spent some time doing a bit more on character design, learned about CSP, and started researching on more formal processes for comic creation.
5) After 5 chapters I realized I needed to improve on my art, and hence, I got this art course and started going through it.
6) I think I didn’t even start publishing the first chapter until I had created... 10 chapters give or take (which is why the first chapters where consistently published every 15 days with no gaps, I already had them done).
And that’s just the beginning. Believe or not, that’s the much summarized version.
Granted if I had to explain my creation process:
1) Write the story at a high level, beginning to end with the main story beats and lore considerations.
2) Break it down in arcs and mini arcs.
3) Break down the first episodes in more specific chapters.
4) Focus on the chapter to work, write out the script in detail (usually 2 or 3 pages long).
5) Create the draft for the chapter. I try to keep it within 10 pages, but during this phase I won’t concern myself with page length, I just try to have a clear vision of how it will read and what the art will look like. By the time I’m done, if its way more than 10 pages (say it’s 18 pages), I’ll simply split it in two chapters, or try to restructure it as needed. I chose 10 pages because that’s what I can realistically do in a month (a milestone for me), or at least in way that makes it easy to manage.
6) With the draft in hand, now I have a very clear idea of what characters appear and what environments are used, so I do some reference designs for myself. I try to focus on doing only what is needed for the chapter, otherwise it’s easy to expand and get lost in doing more material than is needed. One drawing for the environment to have a clear idea of the setting, location of characters and props, one simple version of the design for me to refer to whenever I forget values or small design considerations (like shoes, apparel, textures, etc). I don't worry to much on the quality of the images, since it's just reference material for myself.
7) Then I just go at it, one page at a time. As I work on each specific page, I will usually use the opportunity to further improve it, like frames, angles, refine dialogue and so on.
8) Once I’m done with the chapter, I’ll usually do a “cover art”, which is a nice way to put a seal on the chapter and gives me an opportunity to do more elaborate art than what I do on a frame basis.
9) Finally, translation to Spanish, minor editing, and publishing.
From what I've seen in videos on how mangakas work, they seem to follow a very similar process. I used to be very shy about sharing my work in progress, but now I realize the more feedback I get, the more I can improve on each of these steps.
Also worth noted that a multi-faceted-long running story is usually not recommended, as the commitment, effort and results are usually not appreciable, and can be really frustrating. It’s usually a better recommendation to focus on one shots that are easier to produce, easier to iterate through and easier to share and publish. I usually recommend this video to think about it.
That said, there is no concrete rule. I personally will be moving to shorter, more condensed mini stories in a manner of one shots that still tell the bigger story I have in mind. Mostly because it’s easier to share and for new readers to jump in. I mean, it’s already difficult to get people to take some time to read your work, it’s even harder if they have to go through over 30+ chapters (of less quality than the recent one), just to be able to read your latest work.
I probably answer this partially in the previous answer, but yes, I actually invested some time in defining well the characters, the story beats, and a bit of world building. Though I still consider myself a pantser, I spent some considerable time refining the concept. Probably took me a week or two in just writing every day, but keep in mind I had already refined the idea in my mind for years, so those weeks where mostly spent dumping everything into writing and giving it structure.
However, I still make up stuff as I start each draft. There are many smaller nuances that you don’t realize you need until you are looking at the frames. For example, What do extra characters look like? What items do characters interact with from the environment? Are there main landmarks in the background? A lot of this is made up as I actually draw the final frame by looking at references.
There’s a bit of a story behind it, but I decided to just start right into the plot. This a personal take, but I don’t really like long winded setting introductions, I just want to see the characters interacting and doing stuff. I prefer to learn of the backstory and setting as I go along with the characters, not to have a lore info dump dropped on me.
That said, in retrospective a bit of intro might have been helpful, which is why I know include a little “the story so far” introduction in each chapter, to give the reader whatever context is necessary for the current chapter. Never more than a page though, and usually optional.
I think that’s normal. What has helped me is to just break everything into smaller tasks to complete, and then I can focus on going through each of them as a manner of checklist. That way I can focus and devote all my skill into that single task. It can be frustrating to not see immediate results, but that’s part of the process, to simply be patient and solve each piece at a time, having clear milestones to aim for and knowing very clearly how the pieces go together.
Sorry if this went on for too long, as I said, I tend to ramble since I love this topic. Hopefully this is helpful in some manner, and if you want to discuss further, just let me know.