I get this question on discord a lot so I thought I should make a blog post about it because I've answered it so many times.
I don't really use any special type of writing software other than google docs which i mainly use for the portability. I have a pretty extensive google drive set up. But mainly on my desktop or laptop I make a folder and star it for whatever project I'm starting. Then inside the folder I make an enormous outline which is a bulleted list a couple hundred lines long. It depends on the size of the project which for something like Kills of Her was like 336 listed points.
I then copy about 50 of the bullet points and then paste them into a new document. The outline document I would change the title to reflect 50/336 so that I know I have taken the first 50 to write. Then in the new document I would name it with the abbreviation of the project. Using the aforementioned example this one would be KoH1 0/50.
Then I would go into the document itself and then change the font and color for the actively writing part versus the outline.
Then I can open up my phone and start writing for that 50 first bullet points of material. I usually make a new document for every 5000 words I make because I find that google docs will lag if I write any more than that. The next document would be called KoH2 33/50. And I delete the bullet points as I complete them so I have an advancing strip of story with a diminishing strip of outline / to-do list.
This way works if you're writing a novel without defined chapters, but I also think putting chapters in during the editing phase also works well for me. I have written four books this way as I have a pretty active job where I'm walking around a lot. I would write in bathrooms and subways and waiting in line. It's a very useful way to complete your work. Once you get it, the desktop is pretty not needed, but it's a lot of copy and pasting.
Have fun writing and reading and feel free to continue asking questions.
--Lilse