I have been asked to write a short article about my writing.
I usually start with an idea and do some writing. I try to write at least 500 words a day, six days a week. If I write 2,500 then that is a chapter, therefore I write one chapter a week and a Novella in three months. I mostly write on paper and type it up afterwards. However, when I wrote the time Backwater short stories, I wrote by typing in about 500 words a day. It was a lot more stressful because I was publishing it daily and had to keep it up for about 2 months. I do something similar now on Wattpad, I publish 250 words a day. So if I write 500 words a day then I can get in advance of myself, finish the book and publish it properly then hopefully get those readers to pick up the completed book from Amazon.
The only time I really planned was if I got stuck on a story line, or if I needed a new kind of world. That was until I read a blog article about a woman who wrote 10,000 words a day and planning was one of the main reasons she hit that count. (Another of her tips was to write about the things that interested her/excited her. If they interested/excited her they would too the readers. What is the use of writing stuff that bores you?) So with this latest book I have planned by writing a short synopsis of the chapter, just a couple of sentences.
I also have an idea of where the book will end up, but how I get there is not usually set in stone. I have found that when writing the current book I have wondered how I will hit the word count of a chapter, but have managed to do it. (However the last chapter was shy of the count by about 100 words.)
The only time I stopped writing daily was when I was sculpting to cover for my last book. You do need at least one day off a week so that you can clear your head.
I am planning to do a three day marathon soon and to write 10,000 words a day and produce a novella. I may plan some of it generally before hand. I have heard that Michael Moorcock wrote the Corum books within three day periods because he was a teacher or something. He wrote when he had a long weekend. I think it is a little too soon to try to attempt it for the next bank holiday.
Hope this helps!