Summer vacation season is well under way and celebrities are taking full advantage of their time off. From Japan to France and every major city in between, these globe trotters sure know how to dress for long flights.

Actresses like Rosie Huntington-Wiley and Mischa Barton know that cozy shoes -- flats and boots, respectively -- are necessary for any long-distance travel. Large carry-on purses -- favorites of supermodels Miranda Kerr and Eva Herzigova -- are perfect for toting around all the essentials.

Whether you're flying first class or coach, there's something to learn from the stars featured in the gallery below: being casual and comfortable is key, unless you're Lady Gaga!

Meanwhile, check out the bags that real Los Angeles girls have in tow.