busyPersonally, I think that the way to reduce parking wastage is to support other transit such as walking, biking, pedicabs, mass transit, etc. The more people use things other than cars, the more those acres of pavement look like a waste, and the less inclined people will be to demand more parking. But if you're in a place that has a shortage of parking, it's very different. Removing the space, or failing to make new space for more cars when you add housing or big business, just sets up for trouble. Then people will hate you and work against you. Lower the demand first.
Wherever you can demonstrate that demand is already way lower than supply, ask what else could you do with that space. Is on-street parking half empty? Put in some bike racks! Is a medium parking lot typically empty? Bring in a food truck or farm stand. Consider a skate dot. A big parking lot, like at a mall or box store, is a candidate for tearing out some of that pavement. You could put in a pocket park, or a new business. If you want to keep the pavement, wall off part of it for a skatepark (you can drop cement or wooden fixtures right over the pavement rather than digging into to make bowls) or paint sidewalk games like hopscotch. If you have a lot of young families in the area, paint "streets" and make it a tricycle park. I know of one mall that hosts a large farmer's market in its lot during summers, and that actually does fill up most of the surrounding parking spaces.