How do I write horror?

>read horror
>pick up on genre conventions
>write book

Same with most genre

Think of what terrifies you (bonus points if this aligns with something that much of society fears), then create a metaphor for that thing and write about it.

>>8935561
>this spooky skeleton represents my mummy taking the router away

>>8935528
write random scary stories without an origins story, meaning the characters don't know and will never know how to beat the spookyness.

There's a horror manga just like that but I don't remember the name

>>8935576
savage AF

>>8935528
Aim for a CSI: Miami episode and miss.

>the unknown
>what inherently frightens people on a primal level
>leaving every ambiguous and up to the readers imagination
>powerlessness

There you go

>>8935576
Actually this isn't so incorrect

First, read some horror. If you're going for unknowable horror, read some Lovecraft and Blackwood. If you're going for old-timey gothic horror, read some Stoker and Shelley.
You can't be a cook until you know what good food tastes like.

Badly, just like everyone else.