Your reputation at a part-time job follows you into your next interview through one phone call.

A part-time job feels sealed off from your future, which is exactly what makes it so useful to the people hiring you next. One short call to a former manager produces an honest, unguarded sentence about whether you turned up and whether you were worth managing. Nobody warns you that the call will happen. It just happens.

Treat the shifts you care least about as the ones building that sentence, because they are. Before you leave any job, finish properly and ask your manager directly whether they would be a reference. Keep their name and number somewhere you will still have it in three years.