Bret Hart was one huge missed opportunity for WCW, which they could - and should - have exploited but messed up, likely due to the overkill of the top liners' contracts giving them creative control over their characters (an option that should only ever be offered to legends in my opinion, never active members of the roster and certainly not the entire top rung)
Firstly, as has been said many times in the past, he should have been painted as wrestling's ultimate sympathy figure, and, as was the intent at Starrcade, he absolutely should have prevented the planned screw job finish (albeit a moment that was ruined by the slow count of Nick Patrick) and supervising the remainder of the match. Then, as Sting and Hogan set up a rematch (but not vacating the title, Sting wears it legitimately), the logical next step is Bret Hart seeks vengeance on Shawn Michaels (obviously not mentioned by name) by feuding with his Kliq cohorts, Scott Hall, Kevin Nash and Syxx. He could have beaten Hall at Souled Out, and Nash at Superbrawl. Obviously this means he wouldn't face Flair in his WCW ppv debut (pointless match/feud at the time) and WCW would have to find a different way of turning Scott Steiner heel.
Not only could this have built up steam and helped get him over quicker (rather than having him beat the long term face of WCW, Flair), but beating both Outsiders consecutively would stand him in good stead for a title shot.
But I would hold off that, for now...
Instead I would favour Hart v Hogan at Spring Stampede, deliberately putting their strongly-hyped match in competition for the ppv buys against Wrestlemania. WWE was picking up steam rapidly with the rise of Austin, but with Spring Stampede just a couple of weeks after WM some people would have to choose between the two, whilst even more would have a serious choice of which Monday Night wrestling show to watch...
Meanwhile, I'd build up Goldberg in exactly the same way as actually happened, but keep Sting as WCW Champion, largely defending against a fractured nWo, until Goldberg beats him for the gold. Hogan doesn't need to be anywhere near the title, nor does Hart, for now.
After finally beating the nWo, I'd have Sting and Hart start teaming up - perhaps here is where Scott Steiner, and possibly Rick, can turn heel - there is no need for Scott to join the bloated nWo (and Lyme likes of Stevie Ray would never join it) - to keep them out of the title picture temporarily, until Bret wins World War 3, perhaps last eliminating Sting, to earn a title shot at Starrcade. That's where I'd have him win the belt from Goldberg in a face v face main event, a year after his debut. This would mean no screwy excess interference, no finger poke of doom, in short 1999 would have a MUCH better start for WCW.
Obviously I've missed a few months but there's scope for tag team or 6 man main events v the nWo, and at the smaller ppvs (Road Wild, for instance) Hart could have faced Hennig/Savage etc. In the fall after the nWo is abolished at War Games, (Hart, Sting, Goldberg & Luger? v Hogan, Hall, Nash, Savage, loser 'disbands' and Savage takes the fall, resulting in his face turn and feud with Hogan), Hart could finally move onto Flair at Halloween Havoc.
No doubt there are flaws in my fantasy booking, and I've tried to affect any changes that my changes would have caused, but by and large I think it's a logical process that would have cut out a lot of the crap WCW featured (Jay Leno should NEVER have main evented a ppv) which ultimately drove viewers away.
The only character I don't know how to fit into all this is DDP, who became super popular at this time.
