4. Put a loner moratorium on when you can sign players you just signed/re-signed
One of the things that really put a damper on team performance is the idea that you can trade away big contracts you just signed for instant assets. The Utah Jazz did this recently with Jordan Clarkson, and Donovan Mitchell, giving them longer deals to, hopefully, make them more attractive to future trade partners. It worked out in Mitchell's case, but it didn't for Clarkson's. Now, the Jazz have to find a way to move Clarkson and get back whatever they can for him.
It's caused them to sit Clarkson, a move that admittedly should have happened, but in this scenario, we're looking at talented players being benched at the end of the season to protect their trade value for the offseason. If you can't trade a guy like Clarkson, who just signed a new contract in the 2023 offseason, until two years into his new contract, then the underhanded tactics of sitting him for chunks of the season will be less likely to happen.
More importantly, you'll be less likely to re-sign a guy like Clarkson at all if you don't think he can help your team. This would, in theory, also affect free agency spending and hopefully get it under control. Only teams with a need for a 30-year-old shooter would come calling, and those teams would likely have less money to spend, so guys like Clarkson who have an inflated contract are less likely to maintain such a high cap figure.
The other aspect is that players who hit free agency who are game-changers, can and will get paid far more due to the teams competing to sign them.