Honestly, I've dealt with this on my own block, and the fix is rarely just telling people to "use the can." Most of the time, it's about removing friction and making the right behavior obvious. Start by checking whether the cans are actually where people walk and wait—near corners, bus stops, store entrances, dog-walking routes, or the spots where litter already piles up. If a can is hidden, overflowing, smelly, or hard to open, people will ignore it or toss trash nearby. Make sure it is visible, easy to reach, and emptied on a reliable schedule. A clean can gets used much more than a dirty one.
Next, label it clearly with simple icons for trash and recycling, and keep the signs short. You can also ask a few neighbors to act as informal "can captains" who notice when a bin is full or damaged and report it. Small nudges help, too: a friendly flyer, a sidewalk stencil, or a quick group chat reminder can make using the can feel normal instead of optional. Don't shame people—make it easy, social, and low-effort. Finally, listen to residents. If they say the can is too far away, unsafe at night, or confusing, adjust the setup. When people see that the bin is clean, convenient, and actually maintained, they are far more likely to use it.