Aickman amazes insofar as it's very difficult to distinguish between stories written in 1950 and stories written in 1979: his style and subject matter emerge seemingly fully grown and developed. Obviously, they didn't really -- Aickman started publishing in his 30's, after years of work on his art.
For all the strange and disturbing mystery of Aickman's stories and the cool, detailed nature of his prose, Aickman nonetheless often took tired horror tropes and rendered them fresh and new by re-investing them with that unexplained mystery rendered so cleanly and clearly that one feels as if one has simply missed an explanation somewhere in the story: Aickman doesn't create mystery with obfuscations of prose style. You're watching a magic trick performed without smoke and without mirrors.
Take "Ringing the Changes." It's a zombie story. But what a zombie story! Or "The School Friend": is it a Jekyll and Hyde story? Sort of. "The Waiting Room" seems like a traditional ghost story until one gets to the ghosts, whose behaviour is both inert and cosmically threatening. "Bind your Hair" makes witchcraft scary and mysterious.
These are great, mid-career stories from one of weird and horror fiction's prickly, mysterious greats. Highly recommended.