@D. FritzMost of my Works in Progress are mostly my Notes, Outline, and perhaps some particular scene(s) or dialog. Character notes, often quite extensive, and most of which won't appear in the story, but they provide a significant guide to motivations for the story. So, I have my eventual "destination" and some key "checkpoints" and extensive notes to guide me through the writing process.
Some of them I have started writing the story. I try to write 3 to 5 times a week, both fiction, and some non-fiction or other writing responsibilities. My biggest difficulty is getting internet access. I don't have any internet access for my computer at home. My car is not working, and the friend who had been working on it (only in his 30's) went blind in one eye and is having other health issues. Thankfully, a recent operation may have restored his vision (we will know in a couple weeks); however, I have no reliable transportation. So, I write, and self-edit, but I can't send chapters to my volunteer proofreader, nor can I upload. I can only access via my phone.
Recently I found some written notes of a story I thought I lost in a hard drive crash nearly 20 years ago. I have been entering those notes, and adding some content, with plans to write the story after I finish other projects. Reading the notes, the gist of the story came back to me (despite my multiple TBIs; I have a hard time remembering current matters; unless I write notes).
When I have "writers block" on a particular story, I write something else. If I just "can't" write new content, I edit. If I have been away from a project for a while, I read through what I have already written, and it almost always comes back to me.