A friend said to me: "You just write so many words a day and before long you have a novel." And of course, that's true. It's so true it's cruel. Because it's not the whole truth. I know because I tried it and it didn't work for me.
The reason it didn't work is that I didn't have a process. I didn't even know I needed one. Before you can sit down to write so many words a day, you have to deal with things that seem to have no relation to the actual writing. It's when you write, and how, what, and where.
It's the goals you set and the rewards you build in. It's how you gauge success and how you deal with failure. If you have any other roles or responsibilities apart from writing--and most of us do--it can get complicated.
A successful process is highly personal, like writing itself, and therefore you can't just borrow one that belongs to some other writer and start your own franchise. Although it's perfectly okay to cheat some bits and pieces from several different writers.
All you young writers out there reading this? You need a way to get through the forest. There isn't a clear path. You'll have to make your own.