How do you handle client scope creep after a project is already finished?

I've been dealing with a post-launch headache lately where a client approves the final build but then keeps dropping "quick 10-minute edits" into my inbox every couple of days.

At first saying no feels like overkill for a tiny fix but after a month those quick edits eat up hours of unbilled time. I'm trying to figure out the best way to handle this without ruining the relationship.

Do you usually set a hard limit on post delivery fixes in your initial agreement or do you transition them to a paid monthly maintenance setup once the main work is wrapped up?