For a one-week trip in 2026, the gold standard is the "5-4-3-2-1" rule to ensure you remain light and mobile. This typically includes: 5 sets of socks and underwear, 4 tops (a mix of tees and one dressier option), 3 bottoms (jeans, shorts, or a skirt), 2 pairs of shoes (one walking, one versatile/dressy), and 1 accessory/outerwear (like a light jacket or a hat). This formula allows for significant "mix-and-match" potential, creating over a dozen unique outfits from just a few pieces. If you are traveling to a warm climate, you can lean more toward lightweight fabrics; for colder destinations, focus on thin "base layers" that provide warmth without the bulk. A major "pro-tip" for 2026 is to pack one "sink-wash" kit (a small bottle of detergent and a travel clothesline), which allows you to refresh your essentials mid-week and avoids the need to pack 7–10 days' worth of bulky clothing. By sticking to a cohesive color palette, you ensure that every top works with every bottom, maximizing your style while minimizing the weight of your carry-on.