Go to your local university library and take out some books. Read the books. Write down what you find in the books. Keep a bibliography. Put it in your journal. Re-read your research.
Buy a stack of post-its. When you hear a good word or your research gives you a good but brief phrase, write it on a post-it and stick it on your wall.
Here is some found poetry based on my post-it wall:
umbrella, or shade
carved box; delegation
centres where griots are trained
museums of the historical word
in general, shade
Listen to “Eleggua” as sung by Ibeyi about 700,000 times. Or, like, something that relates to your book I guess. But since you’re also me, just listen to Eleggua again.
When you find yourself mindlessly scrolling Tumblr, don’t castigate yourself; but do ask, Do I actually want to be scrolling Tumblr right now or do I want to be doing something else?
Keep a writing journal. Most of the time you will write in it, “This is trash.” That’s fine. This is my writing journal word cloud at 100k:
Thanks, Wordclouds.com. Prescriptivists can pry “like” from my cold dead girly millennial fingers.
Start writing a silly second book about pretty boys kissing.
Don’t go back and fix that thing you need to change. Just keep writing. Make a comment in your document to remind yourself it has to change; also make comments to write down future plot points before you forget and the fruits of your Wikipedia harvest in important research areas such as sheep-harvesting vocabulary and traditional Nigerian bridge architecture. Re-read your comments.
Accept that your book is not doing what you want it to. When you figure out what it wants you to do, decide you’ll do that in the second draft.