This video has a powerful message about light pollution – please watch it (thanks to Lia for bringing it to my attention).
I think the best way to make things better right now is to focus on the efficiency of better lighting. The video mentions that LED light fixtures are (usually) better at directing light where it is needed. That’s not inherent in LEDs, it happens because the people designing these fixtures are thinking about it – because it saves energy. With regard to street lights, the really good news is that LED fixtures can do something that other common types can’t: They can turn on and off quickly, without wasting energy. That means that by adding simple sensors to detect when someone is near, a street light can be on only when it is needed. When you combine that with the greater efficiency of the LED as the light source and more efficient directing of light to where it is needed, the potential savings are enormous. In many cases the cost of converting to LED fixtures can be recovered in a few years, and that period gets even shorter as more LED fixtures are manufactured, bringing the cost down.
Of course, reducing light pollution has other rewards, and not just for astronomers! Enjoying the spectacle of the night sky is something that humans have done since the beginning, but we are very quickly losing this ancient experience. We joke about having to go to a “tree museum” to see a tree, but for the majority of Americans it is already true that if you want to see the night sky you have to go to a planetarium.