Some of my ideas-
Short term-
I think that all guns should be registered. Old and new. Every one. We have to register our cars why not guns? Some might say, "well the criminals won't register a gun" and they a correct, so, after all guns are registered, anyone caught at any time with an unregistered weapon would be fined $5000. If caught again jail time and loss of the right to own a gun. Owning a gun comes with great responsibility and I think lawful gun owners would want to shoulder that responsibility to protect their right.
I think anyone who doesn't properly secure their guns so they stay out of the hands of criminals, kids or crazies should have their right taken away and/or face charges depending upon the circumstances of the case. If your gun is stolen report it immediately. Since it would be registered it would be possible to track if used in a crime or otherwise confiscated.
Long term-
Most gun crimes are domestic violence and gang activity. Until we deal with the societal problems that cause these, everything else is wasting time. We have to address poverty, income inequality, lack of mental health services, education inequality, lack of upward mobility, etc, etc, etc.
I fear that if we continue to do nothing serious gun bans will be the only option left.