I would create more stables.
In the attitude era pretty much everyone on the roster was in a stable. That way you could combine several feuds into one storyline and get as many guys as possible into one segment on TV. Instead of having 5 different segments for 5 different feuds, you could have one segment and one match that covered all 5 feuds if the 10 guys involved were in 2 stables.
Problem is every time they have a good stable, instead of adding to it they disband it. Stables and teams never stay together long enough.
I think RAW would be a lot more interesting if the majority of the roster were part of some kind of alliance...
The Shield: Rollins, Ambrose, Reigns
(Never should have broke up. They were excellent together. Only Rollins has benefited from the split and his MITB win and subsequent title reign could have been even better if he had Dean and Roman watching his back instead of Kane and J&J.)
Rusev, Cesaro, Sheamus, Barrett & Neville
(I'm not sure what to call them, but I like the idea of these 5 European wrestlers joining forces to win all the titles. Rusev as World Champion, Cesaro as IC Champion, Sheamus as the US Champion, and Barrett and Neville as tag champions. Some might not be able to see Neville as a heel but right now he's on the path to being another Evan Bourne, so a heel turn would serve him well in the future. Both he and Barrett are Brits so I feel they make the most sense as a tandom and seem to be the furthest away from singles championships compared to the other 3. They could be like a heel british bulldogs.)
The Wyatt Family: Bray, Harper, Rowan, Dallas, Truth
(Much like the Shield, they never should have separated. It has benefited no one. If anything they should have added more guys seeing as how Bray is supposed to be a cult leader. Bo Dallas being the obvious candidate to join, while I also like the idea of a psycho heel R-Truth)
And then you have all the tag teams: Prime Time Players, Ascension, The New Day, Lucha Dragons, Uso's, and MizDow (another team that never should have broke up. I miss seeing Sandow the stunt double)
That leaves only the following guys working on their own:
Brock, Cena, Orton, Ryback, Bryan, Ziggler, Owens, Big Show, Mark Henry, Kane
(Most of those guys belong on their own as they're either monster heels or superhero faces)