1. Casting Is Key

The good folks at Dexter could choose to ignore all of our aforementioned points and still churn out two final decent seasons if they only follow this one last tip. Ever since Season Three, Dexter has largely built itself around the "special guest" of the year. Some of the weakest seasons have coasted by on good praise simply because the "Big Bad" was consistently entertaining.

Note that people tend to forget how much the middle of Dexter's fourth season lagged, all because John Lithgow's awesomely creepy turn as the Trinity Killer was unwaveringly a knockout. Or reflect back to the bait-and-switch of Season Three, which featured the lamest serial killer ever, The Skinner, but also featured Jimmy Smits' hilariously deranged, lispy, BFF-turned-adversary Miguel Prado.

But then look at Colin Hanks, pictured above trying his hardest to look evil. This season was doomed as soon as they placed the Big Bad weight on his scrawny, non-threatening shoulders. Mostly this season Hanks was dreadfully boring, or laughably cartoonish, or both. When we think back on John Lithgow, we remember child suffocation and women slain in bathtubs in cold blood. When we think back to Colin Hanks, we'll remember scenes like this.

Sadly, the great Edward James Olmos couldn't elevate the limp plot he was embroiled in, either. Dexter needs someone who can go toe-to-toe with Michael C. Hall, someone who's not afraid to do a little scenery-chewing. Don't be afraid to stunt cast, either, guys. The more incentives to watch, the better.