Know your own routine.
What time are children picked up, which entrances do delivery workers use, and whom can you call for a problem on the street? A family needs a simple way to check with one another before making assumptions about a stranger. Normal neighborhood life includes guests, service workers, and people who are lost.
Notice the change that matters.
Repeated attempts to open a locked gate, tampering with a camera, a direct threat, or a person persisting around a private entrance after being asked to leave are actions you can report. Write down the location, time, actions, and whether anyone is in immediate danger. Do not follow someone in a car, confront them, or ask a child to investigate.
Give everyone a role.
Tell children to step away from a concerning situation and get a trusted adult. Decide who in the household calls 911 during an immediate threat, who checks on an older neighbor if safe, and where people will wait. For a nonurgent concern, use your local police nonemergency line. A shared report should say what someone observed, not repeat a rumor from a neighborhood chat.
Further reading: DHS See Something, Say Something.