Choosing luggage becomes simpler when you understand the Southwest Underseat Size rules before your departure. A practical personal item should provide enough room for everyday necessities while remaining compact enough for underseat storage. Small purses, lightweight backpacks, and laptop bags are popular options for keeping valuables accessible. Remember to measure the bag when fully packed, as its shape may change when filled. Avoid bulky accessories that could make storage difficult. Checking the airline’s official baggage information before your journey helps you prepare appropriately and reduces the chance of unexpected airport delays.