Not OP but Good question! a big part of NIMBY is driven by how much people's net worth is tied into their residence. So IMO you need to reduce this. It starts with convincing people that real estate is on average not a great investment. There is no way for primary residences to universally (1) be a good investment by beating inflation rate and (2) be more affordable.
This is more of a "cultural" thing, and I think most important.
Following that, in practice there are supply side and demand side methods of driving down the cost of living. The big ones are probably maximum height requirements, minimum parking requirements, and minimum size requirements.