Don’t keep all your warm clothes inside checked luggage

Especially if you are  flying from summer in South hemisphere to winter in the North or otherwise. Like recently I was flying from Australia (where it is summer at the moment) to freezing Europe.
When you are boarding plane in the country where outside temperature is +30 °C (86 °F) not many of us are thinking about what is waiting on other side of the World. Me either. But with so many canceled flights and delays you should expect your luggage won’t be able to reach your destination at the same time you’ll do. So it is better be prepared for unexpected, as it is not much fun to stand with t-shirt in freezing temperature.