I recently learned about the "nuclear sponge" strategy. The US has a bunch of ICMBs stationed in remote areas in hopes of drawing nuclear strikes to those areas, away from population centers[0].
History shows that targeting civilians is by far the most effective to make the opposition concede.
With nukes, you gotta stop your nuclear armed opponent from killing you second, first.
If I had to decide on targets I would go for max destruction in terms of lives. In the initial impact and in the long term. So the biggest cities, nuclear power plants, water supply, food production.
As said when usi g this option I don't expect my people to survive as well.
Judging by how WW2 went, history seems to show the exact opposite.