My WIP has reached a point where I'm thinking I should get serious about splitting it into chapter sized chunks that might resemble the chapters in the final work. I'm wondering when the rest of you do this in your writing. During my work so far I've kept the text in a small number of fairly large files with names reflective of the general action that takes place in that section of the story. However, I've been sprinkling "breakpoint" markers around at places where I have scene shifts. My intent has always been to eventually reformat this into a larger collection of unnamed chapters, probably organized in three parts, using the breakpoints as a guide for the chapter divisions. However some of my scenes are very short and I will probably either delete them entirely or combine them with other scenes. In other cases, the breakpoints between scenes are important because there is a time jump or because of dramatic effect. I'm feeling the need to start working out these details... hence the desire to actually create the chapters themselves. On the other hand, there are a few sections of the story that are still in flux and I could see moving/adding/deleting some fairly big chunks in places. Doing that after I've split out the chapters will be a pain since I'd have to rebalance the chapters and/or renumber them, etc. I'm not sure if that's going to be a real problem or not; I guess I'll find out. Anyway this has made me curious about what others do in this regard. Do you define your chapters right up front, leave that work for the very end, or something in between? By the way, this is a novel length work. My first novel, actually.