Delete disused phone numbers from your contacts
Some of my friends and family have a lot of phone numbers. For instance, if I try to phone my brother my phone displays five options for numbers to call — all of them unhelpfully labelled iPhone or Home.
He only uses one of these numbers — and one of them is now used by what I think is a romance scam chat bot of some kind. So far this has just been a bit annoying, but in an emergency it could be a disastrous — the romance scammer bot seems very kind on the surface, but I get the impression they will not be there for me in my hour of need.
Deleting disused phone numbers from your contacts makes your phone nice and tidy, and reduces the time it takes to find the right number — it also decreases the chances of you sending your life savings to a beautiful robot.