Procedural is not the way to go. You gotta gice  people a resson to tune in the next week otherwise people'll just be  like "eh, that was a fun adventure, maybe I'll tune in next week, maybe I  wont." You dont want that, you want an ongoing story that leada into  the next installment to hook people.
Arrow is actually pretty good at this. Even when they have a bad episode  their last minute cliffhangers tend to leave you curious to see whats  gonna happen next week. Flash used to have these grwat "post credits"  scenes that unveiled a piece of the season's mystery and left you  intrigued, but they seemed to stop doing it for some reason.
		
		
	 
Unfortunately, that approach hasn't proved very successful. The top scripted shows are procedurals. Arrow  and Flash and a host of other serial-centric shows have a consistent  downward trend in viewership as the big hook catches just a few less  people every week. This also prevents the show from getting new life  because the disinterest in previous storylines provides a barrier to new  or returning viewers. Promising another great adventure is, generally,  more enticing that promising a follow up to a so-so adventure. More importantly, a procedural offers consistency in characters and character development. No weird writing to make characters do dumb things, because characters are expected to play their role in a proven procedure instead of an ever-moving plot twist chase.
Plus,  even in a procedural, you still do serial storylines and subplots, so  you get the advantage of the hook. Early Flash S1 did this, with a  procedural storyline and a serial subplot. It wasn't until later that  the procedural elements took up less and less time while the serial  elements took more and more. That's when the stretching happened, and  that's when the show became tiring. Same thing with Arrow, heck, same  with Smallville. 
There are shows that do well with purely serial  storylines, those with shorter seasons like Game of Thrones, Daredevil  and Walking Dead, as well as what I said before, those having multiple  protagonists or multiple antagonists. But that doesn't work with the  Berlantiverse method of setting up a procedural and then phasing out the  procedural and playing up the serial elements while you stretch them so  much they become tiring. If they're not going to do a procedural, then they need to get rid of the command centers and specialists and one-off villains.
	
		
	
	
		
		
			I wouldn't mind "freak-of-the-week" stories... If we at least had reasons to care about the freaks. Someone here mentioned the Batman TAS approach and I think it's a series from which the Berlanti-verse could learn a lot.
There, you were given screentime to care about the villains, some with stories and motivations as compelling as Batman's. 
If you're going to make people watch Flash fight some guy with superpowers, why don't try to flip the perspective?
Also, what happened to mini-arcs and two-parters? Arrow Season 3 was very weak overall, but the Brick mini-arc had everything to keep you interested. A charismatic villain that wasn't handicapped by being in just one episode with a cool (if not exactly original) plan and a backstory and placement that let multiple characters shine.
		
		
	 
Brick was great, and exactly the kind of protagonist that could have made the show shine more. I also liked 'The Mayor' from a previous season of Arrow. Having him expanded would have made the show better as well. Those characters open up great political storylines and give the relationship drama stuff a chance to breathe, or a context that adds weight. But, I don't think they're interested in that. Also, in any good procedural, the issue and heart comes from the victim of the thing that needs to be taken care of. That focus on the victim is, oddly, missing from a lot of superhero shows, which, ostensibly, are about saving people.
I suspect they, and many other failed/failing shows, use the most vocal fans (i.e. 'shippers') as a dipstick for their audience, and they play to that. Unfortunately, shippers aren't a sustainable audience. They latch on to something that's already in progress, something that already has meaning, and they find their joy in scouring things that are *not* relationship drama, but genuine character moments in the midst of other contexts. So in catering to shippers, and focusing on relationship drama, you deprive the heavy shippers, casual shippers and non shippers of the context that makes these character relationships meaningful. Fewer and fewer people are interested.
Do you know what would really inspire me in one of these shows? A genuine committed relationship that is entertaining to watch.