Awesome packing tip called a skivvy roll. Teaches how to save space in your luggage every time you travel. Budget travel lovers will enjoy this technique because it can mean less packed luggage (and fewer fees).
I have wasted countless gallon ziplock bags when traveling - just unscrew the lids and put some plastic wrap over the opening then screw the lid back on for a much easier spill solution! (not quite as safe as a plastic bag, but a good idea!