I think the worst possible situation is what we have now: Judges magically allowed to practice indefinitely, becoming more corrupt year after year; on the take in all likelihood (otherwise no clear explanation for their outrageous decisions); more clueless and detached from the realities of crime and criminals; growing indifferent and then actually hostile to the fates of victims; fuzzier and more rotten judgments, until they are either sleeping during cases or outright senile or crazy.
It's the rule rather than the exception of judges not strictly term limited.
So for me I would like them to have to run for reelection every four years, maybe fewer.
Also make them much more easily impeached for crazy decisions.
Some personal liability for their decisions leading to the deaths of innocent victims when just keeping someone incarcerated would be the status quo.
If THAT happened, this ridiculous revolving door stuff would stop like yesterday.
50 district Courts, one for each state. Their judgements would only apply to their own state, each state would make make its own set of rules for how long judges serve and how they are selected.