If it’s a series I really enjoy, I don’t want it to end (I’m kinda going through that right now as I’m on book 4 of Caro’s LBJ books). So I usually read 2 or 3 books in-between the volumes. I did the same with The First Law Trilogy (by Joe Abercrombie) and with The Sound of the Wind I just stopped.
I really only have 2.
Robert Caro: yes. Historical non-fiction and he only has 2 subjects he’s ever written about. But there is so much to learn from these books, and they’re so well written and riveting, there is endless re-read potential
Joe Abercrombie: I love complex characters and character development so I could spend ages studying the characters in his books (this is also why I love Caro)