Basically, I do all this research and then end up using only the smallest fraction of it in my work.
Take RUSH for example. (and no, that's not CAPSLOCK OF FURY, that's just how it's spelled). For RUSH, I researched the hell out of two main areas: blindness and musicality. I called foundations, I listened to concertos, I read testimonials from blind people, I interviewed a concert violinist for the finer points of auditions, and I learned a lot of music lingo. And of all that research, I'd say only a good 20% TOTAL made it into the book.
Instead of acting as a conduit to the plot, my research acted as a big fact roadblock. There's a scene in the book where Noah and Charlotte go to a party. There, Charlotte and other musicians play the themes to popular TV shows. The first draft of the scene where they play was three pages long and full of awesome-sounding terms like intervals, and descants; cadences and dynamics. It was all so authentic and accurate and smart. It was also completely fucking boring. Because who cares? I wrote it to show that Charlotte thought like a musician and that she spoke that language fluently, but the result was a serious dump of boring terms some people would get, others would gloss over.***
I have one hard and fast rule I stick to in my writing, learned from Stephen King in his invaluable memoir/how-to On Writing. The rule is: IT MUST SERVE THE STORY.
I get some flack for starting my books out slow but that's one criticism I don't cuddle close to my heart necessarily. I don't want to bore anyone, but I also like to lay a good foundation, and every single thing I put in my books must obey the law and SERVE THE STORY. (Every single one of my Chekovian pistols I set on mantles in Act I get fired by Act III, without fail.)
So when I reread that music party scene, I realized all those fabulous terms weren't doing a thing to serve the story. What was more important was that Charlotte felt alive in her music for the first time in a long time, and so out went all that glorious research but for a few key terms, and in went a focus on her de-thawing. Also kept, her audition process for the Vienna Touring Orchestra, although severely truncated. I had a full audition written with her playing scales and a piece of their choosing, yadda yadda, but the only part that served the final cut was her NAILING it and winning the seat.
I wish I had been more cutthroat about other aspects of research for RUSH, as I nearly wrecked the book with it--unbeknownst to me--and I would have saved myself a ton of time and headache.
I did a ton of research on blindness, specifically technologies and skills to help those learn to live with their disability. This research manifested in a plot turn where Charlotte goes to a foundation on the sly, to learn tips and tricks for being a better assistant to Noah. Sounds pretty good, but what I actually did was dump a huge boulder in the middle of the book and then spent nearly an entire month trying to write around it to make it fit. I had a potential third-party love interest; I had lessons on how to use a white stick; labels for food and appliances, etc etc. And I couldn't, for the life of me, figure out how to progress the love affair between Noah and Charlotte around her secret visits to this place.
So I took another piece of advice that comes to mind whenever I'm stuck. "Go back to where you were doing well. Just before, or right after that spot, you will find the problem." So I went back to when I was doing well, and it was just before Charlotte's first visit to that foundation. So I cut it all. Probably close to 15K words, and OMG it was like winning the writer's lottery. All of a sudden, everything was flowing again, and all that research went down the toilet where it belonged.
This is not to say I'm now back to knocking research. Hells no. But here's what I learned, and maybe it'll help other writers: Research the hell out of something and let it seep into the novel. Let all that you've learned come out organically, not in a great show of terminology. Don't try to shoehorn in a bunch of new stuff simply because you learned it. Everything I researched about blindness came out in Noah's struggles and Charlotte's kind-hearted attempt to help him, because those things served the story which is, at its essence, not about how to fold money so you can feel its denomination, or how a violinist would approach the eerie whine in Walking Dead. It's a love story and therefore whatever I researched ultimately needs to serve that first.
And never has this been more true than for Beside You in the Moonlight, my latest that is:
1. set in Paris
2. in 1971
3. involving the Vietnam war
4. protest culture
5. minor-league soccer
6. Mountain geography
7. a SPOILER ALERT plot twist
In short, there's a shit-ton of research I'm doing/have done but this time around I'll remember to let it flow out with the rest of the story because I could talk with some confidence about Operation Dewey Canyon and the Battle of Hamburger Hill. But wouldn't you rather read about Zoey and Tristan coming together in war time, instead of the particulars about the war? Because that's the story I'm writing.
*** I've seen books heavy on research terminology and not one word detracted from the plot or story. It was woven in beautifully, so on this, as with any piece of advice on the subject of something as subjective, YMMV.