How long do you usually take to plan for a really long story/comic? Do you do a rough plan or a fully detailed one? Any apps you use for planning?
It depends on the project. For my long-term series, it definitely takes me a good while to finalize everything from start to finish, but as a general rule, I try to keep my writing one step ahead of where I'm drawing, for two purposes: so I can have a goal in mind to propel the comic forward (I don't want to be writing or drawing on the fly more than I have to), and so I can have enough planned ahead for editing, because by the time I get to the thing I've planned, my writing has likely grown more and my perspective on it has shifted, so I'm not releasing "first takes", so to speak.
Usually I use LibreOffice and just sort of keep a few separate files for different purposes. I always have a "[story] shit" file of some kind where I just dump thoughts and notes that I don't wanna lose lmao but then I usually also have a file that's meant for outlining. I think Rekindled is the first comic where I haven't employed my spreadsheet method, which is when I'd use Excel/Spreadsheets to lay out panel descriptions and dialogue. So like this:
(Episode 14 of Time Gate: [AFTERBIRTH])
Rekindled is more just note-taking, what I want to happen in each episode, and if there's any dialogue I come up with that I definitely want to include, I write it down in there. I've done all of Rekindled's process through Scrivener, which I learned how to use shortly before starting it. IDK yet if I like Scrivener enough to use it for my bigger projects, but it's been helpful for organization and keeping my files all in one central "hub" area.
So right now I have up to about Episode 70 drafted out like that ^^^ but things do change during the actual production of the episodes. Sometimes I'll write something in my notes that doesn't flow well in actual comic form. Sometimes I'll write dialogue during the sketching stage that I don't like anymore by the time I get to the final rendering. It's all a stage-by-stage process from drafting to final release.
The question of "how long" really just comes down to the note-taking process. I tend to work in bursts, the last time I did any written episode layouts was a few weeks ago and that was because I got like, 40+ episodes done in a day LOL So I'm all set for the next little bit, but I'll have to get back to planning by Episode 50 if I haven't done any before then. I'd like to have the entirety of Rekindled plotted out by the end of the year so I can get a more exact answer of how long Rekindled will be :' )
When it comes to software/apps, keep it simple, use what you know. I've been using standard word editors and spreadsheets for years now because it works for me. Scrivener's been fun to learn but as I mentioned, IDK if I'm gonna be able to stick with it for bigger projects like Time Gate because it feels like I'm wearing different shoes that I'm not used to lol But that's just me, feeling "at home" with my software is just an important thing to me, for others it might not matter so much. Scrivener definitely has the most features for drafting/writing/editing, but it's also not very beginner-friendly and there's a huge learning curve to really understanding how the software is designed and what it fully offers.
There's also Plottr which I've been using for [AFTERBIRTH], it's really helpful for people who need visual aids because it allows you to lay out story timelines through imagery. But I really only use it for laying out story beats from end to end, I don't use it much beyond that, any extensive note taking or scripting happens in actual word documents.
(idk if this is how you're actually supposed to use Plottr but it's how I use it so w/e lolol)
Ultimately it's all up to you, what works for me might not work for others so don't be afraid to try things even if it ends up not working out for you. Obv that might be a bit more of a "nah" when it comes to paid software like Scrivener and Plottr, but there are loads of tutorials on Youtube that teach you how to use the software that you can hopefully use as a glimpse into how they work to see if they'd be up your alley before paying money for 'em.
Hope that helps! ˋ( ° ▽、° )