In a froum about writing I just read: “I have a problem of writing so many books and end up not finishing them. How can I finish writing a book without any distractions?”
Oh, there is your demon, called ‘Creativity’! Embrace him (or her) – and take notes (not more) for potential projects. Now, here is the ‘but’ – don’t start them and keep working on the one you desire most. Ask yourself “What is your heart ‘burning’ for?” (Can one say it that way?). THEN make a plan with milestones – AND reward yourself after achieving one. Such a plan can be simple.
For example some twelve years ago I wrote a novel for the game FarCry 2 as contract work (in German, in case you are wondering what language that is on the image).
Now, what did I do? I broke down how long the novel had to be at least (according to the contract) and than mapped the events over it. Thus I gained control over the chapters and the length of each chapter (approximately). And when I achieved a milestone (here the end of act I) I celebrated it, e.g. going to dinner with my wife.

When you finish your goal (here, the first draft of the novel), celebrate it again! Invite some friends or something! When I finished the first of the three Runes of Magic novels, we celebrated it (and I signed the bottle to remember the date).

So in essence: Make a plan – and stick to it!
Good Hunting!
Mike
PS: The advantage of contract work is, that you get paid – and that you have to pay a ennourmous fine if you do not deliver in time and budget. Somehow that motivates to get each Saturday up in the morning at 0600 to complete your novel. 😉