the best book I've read on the subject of advice for mystery novels is this one, lots of nitty-gritty details.
https://www.amazon.com/Writing-Selling-Mystery-Revised-Expanded/dp/1440347166/ref=sr_1_1?crid=3M2K9HJY30L5G&keywords=hallie+ephron+writing&qid=1642513049&sprefix=hallie+ephron+writing+%2Caps%2C98&sr=8-1