Aa I finish a chapter, I write a note of three to five sentences detailing the main points of said chapter—later I scan through them to refresh my mind on what I've written and where I still need to go.
For those using Scrivener, it has a digital version of this tried and true technique that @Mary J Hicks mentions . The Cork-board view allows you to highlight the main points in each chapter (or document/scene within a chapter) without this information being included in your compile.
This may be a problem for me. I have been writing a lot in the past six months and finished two novels but I do very little planning, if any. I would argue this isn't always a bad thing. There's a certain natural feel to writing as you go along and any writer knows the narrative takes twists and turns along the way. You often don't fully understand the characters or subplots or themes until you've gotten to know them. I had the idea in mind and the main plot but I had no idea what shape any of my novels would take...but as I look over my last one you sometimes do worry if it's disjointed. I don't think it's too noticeable, but you are faced with choices as you go along and I realise that I could flesh out my plot here or go in a different direction there, but ultimately, to keep it under 100k I choose to take the shorter route. I guess it all depends. I am going to try planning my next one a bit more but I don't like to go overboard with this. I think it's good to have an idea of the sequences in a story and that way it may look more professional but it's good to start what you finish too.
One of the best things you can do, every time you start writing a chapter or scene is ask yourself a particular question. "What do I want this chapter (or scene) to accomplish?" Literally, ASK yourself that question and make sure you answer yourself! You can even go so far as to write the answer down, and keep it beside your computer. "What do I want this chapter (or scene) to accomplish?" Answering that question will keep your chapters from wandering off in all directions. I'm the sort who writes my chapters out of order, so I've got to be sure each time I start one that I'm not, in effect, starting a new story. You don't want to focus on what happens. You want to focus on WHY it happens. It's a good question because it doesn't tie you to a particular way of accomplishing your goal. It gives you a lot of leeway in that regard. However, you don't quit the chapter until you have accomplished what you set out to do with it. Examples: I want to show why my character hates her home and wants to leave. Or, I want the two young men to meet for the first time, and I want both of them to realise the other is a potential rival, even though they actually get along well. Or, I want to establish what the port city is like, and show how difficult it's going to be for my character to make a success of her life, when she finally gets there.
I can't like this enough; asking that question got me through rewriting my WIP and kept it focused, along with actually keeping me writing.
I don't wear makeup in the slightest, but I get the analogy. I also relate to the 30K thing, because that used to always be the point where my novels would fall apart and become poorly-structured and dysfunctional. I think it's because, if you're writing a novel that has a common word count of 90,000-110,000ish, then 30K just a little ways after the first plot point - not the hook, but the place at around 20% where the buildup is over and the arc of the story is set - I think this is the point where you have to get more logistical with making sure all the puzzle pieces are fitting properly, and it can be more challenging. I think that in my case, the midpoint sequence I just wrote might be more of a climax sequence, and I may need to beef up the early/middle point of the story, especially with regards to character stuff. I'll review the whole thing before making any big decisions, but as I've made further progress, I think this will tie things together and fix a lot of my perceived problems.