For travel in 2026, the "golden rule" is breathable, high-stretch layers that can handle shifting temperatures from the terminal to the tarmac. A pair of high-quality joggers or technical trousers (like those from Lululemon or Vuori) is preferred over jeans, as they allow for better circulation during long periods of sitting. For your top half, wear a soft t-shirt or tank top layered under a versatile zip-up hoodie or a lightweight "shacket"; aircraft cabins are notoriously unpredictable, and being able to shed or add layers is vital. For footwear, slip-on sneakers or loafers are the smartest choice to expedite the security process, but ensure you wear socks to avoid walking barefoot on the airport floor. Many travelers also swear by compression socks for flights longer than four hours to reduce swelling and the risk of DVT. Finally, avoid "noisy" jewelry or belts with metal buckles to minimize delays at the X-ray scanners.