Large writing projects are intimidating for many writers. It's easy to fool yourself into thinking that if you're working on a large project like a book, you need broad swathes of time to accomplish anything. After all, if you're writing a book, you can't get much done in ten minutes, can you?
In fact, the opposite is true.
Like the old joke "how do you eat an elephant - a bite at a time" you get more done on large projects if you chunk them right down. This is especially true at the beginning of a large project.
Large project startup: word by word
I start large projects by creating a project definition - a mission statement.
For example: "This is a suspense novel about a woman who appears in a small town, marries, and then disappears. Her new husband is charged with her murder. The story is told from the point of view of the husband's newly widowed sister."
Or: "This is a book about time management for writers. It covers motivation and strategies, as well as common challenges."
Once I've written the project definition, I can noodle on the project, writing small chunks of it. I might spend ten minutes free writing, writing a character bio, outlining, or writing a few hundred words of first draft material. I constantly refer to the project definition, because large projects tend to morph as you work on them.
As I become more comfortable with the project - I have a better grasp of it - I can schedule longer writing sessions. If I become intimidated by the scope of the project, I go right back to working on tiny chunks.
If you've been too intimidated to try a large writing project because you "don't have the time", try this chunking method to see whether it works for you.
My ebook "Top 70 Writing Tips To Help You To Write More" gives you many additional tips you'll find useful in working on large projects, as well as small ones.