Since security rules require you to separate any liquids in your hand luggage into clear plastic bags, it is always a good idea to bring spare bags in case you lose one or if you're buying tiny travel liquids last minute. While most airports hand them out for free, we have heard stories of people being charged for bags if they don't come prepared. Also, be aware that some airports will limit you to one bag per person. Check the airport website before you pack that hand luggage.
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