Spread out the pain so everyone only suffers a little. Spread out the development across different architectural eras. Spread out density to the point where you have diminishing returns.

The city shouldn't be changed overnight, but the city should be allowed to change an a consistent rate that slowly accelerates. A good example is to allow each building to only double the square footage of the median building within, say, a quarter-mile radius of the property being redeveloped. This means that SFH's can only become duplexes until duplexes are the norm. After that, quad-plexes can be built, and then when that's normal, you start building large, eight-unit, european-style flats.

This allows different areas to grow at different rates, while allowing density to remain generally uniform across neighborhoods. This incentivizes people who very much want low density to have a reasonably, predictably low-density neighborhood to invest in, while giving up the ghost when a piece of land is just to valuable to reasonably keep low density.

It would work, and would work quickly in areas where lots of development is needed.