Good article, thank you. Loglines are easier to write in pithy terms, when describing someone else's work (eg Black Narcissus: Sexually frustrated nuns go mad in the Himalayas).
When writing them seriously, for my own novels, I find it a lot harder. I can just about crack it though, with effort. Here are loglines for five of my gothic mystery horror/thriller novels:
The Birds Began to Sing: An aspiring novelist enters a mysterious writing competition at a sinister mansion.
The Irresistible Summons: A television producer who debunks the supernatural encounters a genuine haunting in a London office block.
Phantom Audition: The grieving widow of a famous actor begins to suspect a supernatural hand at work in his apparent suicide, linked to his final acting role.
The Thistlewood Curse: A detective and her paranormal consultant suspect supernaturally assisted murder after the sudden heart attack of a Lord's son on Lundy Island.
Spectre of Springwell Forest: After discovering a mysterious painting in her attic containing a gradually revealed figure only she can see, a mother comes to believe her young daughter has been cursed.