Basically what the title says. Any tips on writing psychological horror/thriller. The story im currently making is influenced by Heart Of Darkness/Apocalypes Now and Spec Ops The Line but i never written a psychological anything before. I understand that HoD and A.P is a mans decent farther into hell than he already is but i never understood how they changed over time with each stop they make. So yea are there any tips on writing psychological horror/thriller?
Personally the thing I like most is the Unknown, so keep the reader guessing. If a character does something bad, make the next thing they do heartfelt and kind. It's not much help, but its all I can offer on such a broad theme.