How much breathing room do you actually leave between flights?

A connection can look perfectly reasonable on a booking screen and feel very different when the first plane lands late. Add a terminal change, a tired child, or a suitcase that has to be collected, and the cheaper itinerary suddenly looks less attractive.

How do you decide whether a connection is worth taking? Interested in the details that change your answer: one ticket or separate bookings, an unfamiliar airport, mobility needs, and whether missing the next flight would ruin the whole trip. Share the buffer you prefer and the reason behind it.