The beauty world went mad when influencers Marianna Hewitt and Lauren Gores Ireland launched their first skincare product, the Summer Fridays Jet Lag Mask (£42). And while the duo's Insta-fame helped garner initial buzz, it was their genius formula that kept people coming back for more. It's made to combat the dryness and dullness caused by stress and air travel, so I always make sure to toss a travel-size tube in my carry-on. And when I'm not flying, I like to use it as an overnight mask, layering it over a hydrating serum to really lock in all that moisture.