Less convoluted outlines with numerous tangents and an obsession with always involving angels and omnipotent beings in the brothers life. Return to what worked, 2 brothers backs against the wall fighting with and for each other against a real monster with minions and henchmen the brithers have to get through to get to the gead guy. Not the brothers fighting each other and not one of the brothers afflicted, sick or shouldering the burden with some big trial. Stop with the endless tangents that never lead anywhere.
No more bad angels EVER. I want evil looking monsters and yes that means getting some real make up artists not just CGI everything with black eyes. Crowley should be limited and when present play bith sides good and bad like he used to, no more Crowley with feelings or hanging out with the brothers.
Set design: yes, I said it, go back and look at the first season, the director of photography and set designer created an atmosphere of fear that enhanced the stories. Also, more Impala and rock music is always good and that has not been around for a long time.
Stop killing off everyone, the brothers need allies and to kill off every interesting character feom Bobby to Garth leaves you with no one to build stories around. The brothers need to go back to the detective work and traveling from town to town as well as the MOTW.
I know everyone is frustrated and I have been as well, all we can do is hope for a better season next year.
Get the brothers happy again. They'll never be like Seasons 1-3, but how can we be invested in such a crappy relationship if they're fighting and miserable most of the time? I'm even cool with some "curing the codependence" if it comes out to them interacting happily again.
Write Sam, dammit! Every season, it's "something's wrong with Sam" and other aspects of his character have suffered for it. They don't seem to know what to do with Sam unless he's "altered" somehow, and they don't seem to know who he's supposed to be anymore (and it feels like whenever he's "normal," he's fighting with Dean). I want more Sam like in "Mother's Little Helper." Mature, capable, compassionate for the people he deals with, concerned and level with Dean without nagging or picking fights. The last couple of episodes have frustrated me because he could have had serious interaction with Gadreel and Jodi, and nothing happened.
More MOL. You got this awesome bunker with a zillion supernatural items and secrets. Use it.
I'd love to see more Lovecraft or Gothic focus. Hell, give me Frankenstein monsters, Eldritch abominations, maybe not so much on the vampires.
And just for fun- cross-breed monsters? Like, can a demon possess a werewolf or vampire? Can a vampire "turn" a werewolf or vice versa?
Hell, put me on the writing team, I'll have it covered!