One of the constant concerns is pacing. Because the short chapters range from 5-9 pages the events have to be compressed to fit, and sometimes I realize I have made two--or even three--chapters out of something that really only needed one.
So I spent this morning turning twenty chapters in one of the storylines into fifteen chapters, by combining chapter content and changing the emphasis points--and re-polishing the little cliff-hangers at the end of each chapter. But more than anything, I eliminated re-descriptions of things the reader already knows I had used as set-ups to more compelling stuff.
The story rolls so much better now.
It can be useful for any writer to reread each chapter and see what it really brings to the story. If the event you are excited to write occurs in the middle of the night, after the protagonist comes home from spending time with someone that you know they are slowly going to come to love, it might be worth painting a full scene with that person, then letting the protagonist get ready for bed thinking about the evening...and then be awakened by whatever the midnight surprise scene is.
But if the protagonist spends the evening with people less important in her/his life, and the reader already knows what their roles are in the protagonist's world and is equally familiar with the physical layout of the apartment or house or campground (or whatever) consider a chapter opening that has almost no set up:
quick example: ** (this is not from the book in progress, just examples I am making up now...)
For a moment, Jenny thought the pounding was imagined, part of a dream. Then she thought it was coming from the street. She sat up in bed, confused and scared, tangled in the sheets, finally awake enough to understand that the banging was close, meant for her, and not muted by skin or flesh. Someone was pounding her door with something metal, someone was trying to break it down.
As opposed to:
Jenny got home late and took a shower to relax after another long day at work. Gregory had been tedious as always and sometimes she wondered how she could stand to work there, but she knew she had to. Nothing had changed. She had to support herself now. It look a long time for her to go to sleep, then, in the middle of the night, someone pounded on the door. For a moment....etc.