What worked for me

The thing that got me across the finish line was that ths was not my Great American Novel (tm), but my Hello Novel. Just as in learning a new programming language, I didn't set out to do something amazing, but to learn the mechanics and syntax and rhythm of writing, so that I can eventually write something good. So I sat down with three of my most entertaining books in my chosen genre, then sketched out when in the story things were supposed to happen.

For example, I might have noted that the two main protagonists should meet within the first three chapters and that they should have a minor conflict upon their first meeting, stretched out over a few scenes. Their personality sketches should be done within x number of pages from the beginning. Or I might have taken note that they should have their major conflict 3/4 of the way to the end, and how many pages are used up in the high-stress scenes. I didn't have any idea what was supposed to happen -- no story arc, but I had a story architecture, in essence.

This was great for me because as I would falter and run out of ideas, I would just look up where I was supposed to be in the story, then make something up that fulfilled that function. It was fun because I was learning the story as I wrote it.

This year, I am going to have a more complete story arc pre-planned.