STEP ONE: STOP MAKING MOVIES (FOR NOW)
I imagine there are many out there, like myself, who are feeling a bit of a burnout with comic book movies, series, television shows, etc.
Solution? Let the current shows wrap up and then give viewers a year or two without any comic book related stuff, and focus more on original-ish lower budget "popcorn munchers" like what Stephen Sommers and/or Michael Bay crank out during the summer, and a slower, character driven piece or two during the winter unlike what Sommers and Bay would do.
STEP TWO: STICK TO ANIMATION
I get it: bigger studios want to avoid the so-called animation ghetto and make superhero features for older audiences. Thing is, that medium has forced more . . . "established" characters and plot lines to be discarded in favor of more grounded, realistic fare. Animation provides more liberty with what can be shown on-screen and I'm assuming for a much lower price like with, say, Castlevania.
Speaking of said ghetto, shows like the aforementioned Castlevania have all but razed that stereotype to the ground. May as well take advantage of it.
STEP THREE: TAKE CHANCES
I get it: Batman translated well into other cultures, so having the Dark Knight hijack films that wouldn't require him made cents (pun intended). Glaring at you, Justice League: Dark (with BATMAN). I get it: Darkseid and his cronies make for a great threat that only the Justice League (with BATMAN) could hope to defeat.
There's more to DC than just the Bat, though. Not saying Marvel is innocent, but DC's Bat-fetish is the most Bat-prominent.
Case in point: the four attempts thus far at making a Fantastic Four movie. Things may work just a little bit better if they were given a twelve, thirteen-ish episode season to help with those little but necessary things like emotional investment. There's a reason Slade Wilson from the Beeboverse is so well-regarded and it's not (entirely) because of Manu's charisma.