Some airports, like London's Heathrow, offer sleeping pods where you can catch up on rest between long flight transfers. Pay around £30-£40 for four hours (minimum) and you can take a shower (body wash and towels are provided) and enjoy a comfortable nap (not on the airport floor). If you're travelling internationally, check to see if your airport location offers this sleeping amenity, or see if on-site hotels will offer you a room for a few hours at a reduced rate (doing this at Shanghai's airport hotel was the best decision we ever made). Alternatively, just get comfy in a quiet spot and snooze.
Image Source: POPSUGAR Photography / Mario del Rio
Product Credit: 3x1 top, Iconery earrings, In God We Trust bracelet