Any P.I. who flashes a photostat of their license. I mean, photostats? Who uses that term anymore? Hello! It's not 1929, anymore. And by the way, gunsels aren't actually guys with guns...

Excessive references to jazz. Nothing wrong with jazz, really, but jazz snobs are a dime a dozen these days. Anyone fifty or under who listens exclusively to jazz is probably a geek or a snob. It's more likely they grew up listening to the Stones or the Sex Pistols or Garth Brooks or Elton John or Nirvana or Motown or soul or Public Enemy or the Beatles. And chances are they're still listening to 'em. There's no shame in admitting pop culture exists. Name-dropping Mingus or Charlie Parker doesn't make you an intellectual.

The detective should be a man or woman of their times.

Private eyes who drive classic automobiles or brightly-coloured sports cars. What sort of idiot tails someone in a car that draws attention to itself? Can't you just see it? "Hey, Mugsy, isn't that the same 1955 cherry-apple red T-Bird convertible in immaculate condition, with the mag wheels and the white pinstriping that was behind us yesterday?" "No, Bugsy, it must be another one."

The bourbon in the drawer.

The fedora and the trenchcoat.

The stacked secretary.

The psycho sidekick who does all the dirty work that the virtuous P.I. won't.

The treacherous femme fatale.

Obsessive fitness.

Tedious subplots and tragic pasts force-fit into the story to make the P.I. look more human, or have more depth, with no connection to the main plot.

Faux literary self-reflection after using violence.

Extensive Vietnam flashbacks.

Serial killers.

Let's put political correctness on the hanger next to the lime green leisure suit. And gratuitous political uncorrectness right beside it