When packing for Chengdu, focus on adaptable layers to manage its humid subtropical climate and varying seasonal temperatures. For clothing, include moisture-wicking T-shirts and breathable fabrics like cotton or linen for the humid summers, while bringing thermal base layers, wool sweaters, and a heavy coat or padded jacket for the chilly, damp winters. Regardless of the season, a lightweight waterproof jacket or sturdy umbrella is essential due to frequent rainfall, and comfortable, water-resistant walking shoes are a must for exploring the city and nearby mountain areas like Mount Qingcheng. Essential health and hygiene items include pocket-sized tissue packs and hand sanitizer, as many public restrooms do not provide paper, along with a personal medical kit containing antacids and anti-diarrheal medication to help with the local spicy Sichuan cuisine. Don't forget technical necessities like a universal power adapter (Type A, C, or I), a power bank under 100Wh, and a smartphone pre-loaded with essential apps like Alipay or WeChat for payments and a reliable VPN to access restricted services. Finally, ensure you have your passport with a valid visa, printed copies of travel documents, and a small amount of local currency (RMB) for emergencies.