Well loaded question with a non specific answer, with the release of crimes 2.0 those in 2.0 have only a vague nnb to ce corelation like la Croix tasting like the fruit it claims to flavor it.
Nnb increases are triggered by "hidden" triggers not ce gains. For example we have a 60 nnb that is lower in ce then several 50 nnb players and a 70 nnb that is higher in ce than several 80 nnb players.
Back in crimes 1.0 it was the goal to spam arsons or kidnap mayor (provided you kept cash on hand for the bribe) to raise ce that was the sweet spot of ce gain per nerve spent. There are several test underway to determine ce gains with crimes 2.0 it will take time to get the clarity we had with crimes 1.0
Edit: if your goal is to increase nnb there seems to be a coronation with merits within each crime type to increase nnb but that may just be anecdotal currently