We save some of our empty water bottles when on holiday. Then we pour any spirits we have bought into the plastic, label them up and keep them in the garage when we get home. We then top up the glass bottle we have at home when it becomes empty - doesn't happen very often at all
This is not only to prevent breakages on the way back but plastic weighs less than glass so we don't have the worry about the excess baggage on the way back.
That's our excuse anyway.