C'mon, tell me if I've been doing it right all these years.

Yup, dead right. By doing the earths first, you common the 0V DC level, and then by doing the dead positive first, you prevent a discharge (spark) as you connect the positive from the running engine to the flat battery of the dead one. The spark is the killer.

When you unwind, you first stop the engine of the car providing the jump, then take the cables off in the reverse order.

One of the few remaining Mk1 owners... #00015