Force individual officers to carry liability insurance similar to malpractice insurance for lawyers and doctors. If the insurance is forced to pay out a couple times the officer would be uninsurable and thus unemployable.
This is suggested quite often, but no one is going to sell you a liability policy to protect you from committing crimes.
When police officers commit blatant misconduct the officers involved should at least be fired and criminal charges should be applied to them if applicable. This is how it works for every other job, not sure why police should be different.
But is that accompanied with officers being exposed to individual liability? And removing qualified immunity? Because that would be the bigger argument.
Limit qualified immunity and require officers to carry personal liability insurance on the job.
Increase police training requirements. They're woefully undertrained in the US (at least relative to Germany and several other Western European nations).
National LEO registration or something similar to stop the movement of bad officers from one department to another.
You are right but its not merely the degree of training but how they are trained as well. As it stands many are trained that every interaction with the populace might get you murdered and you ought to be ready to murder them first.