u/Nuffin8

Like in Japan, the way toilets have the wash basin built in to the cistern, so the water wasted washing your hands is recycled for flushing the toilet.

Or the way communal bins are provided for each local area/street in Spain, meaning wheelie bins are non-existent. I'm sure they have some issues around them, but at least all footpaths aren't clogged with lines of bins. It also means dog-walkers have bins readily available on every street to drop the poop into, might save them hanging it on a branch...