Every outside door, not just the front
Ask someone how many locks their house has and the answer is usually two. Walk around it and the count climbs: the front door, the back door, a patio slider, the door in from the garage, a side gate, a shed, sometimes a basement entry. Condos add a unit door, a storage locker and a mailbox. Each one is a way in, and each one deserves the same attention as the door with the welcome mat.
The first job on a home visit is that walk-around. Every lock gets looked at, you hear which ones are fine, which need a new key and which have worn past saving, and nothing is touched until you have decided.
After a move, nobody can say how many copies of the old keys exist: past owners, their relatives, a dog walker, a contractor from three renovations ago. A rekey of every outside lock settles the question in one visit.

