When it comes to packing underwear for a week-long trip, striking the right balance can really improve your travel experience. From personal experience, packing at least two pairs per day along with one or two extras can be a lifesaver. Sometimes plans change, or you might sweat more than expected after a long day of exploring. Having extra underwear means you won’t have to worry about finding laundry services immediately. Interestingly, some travelers pack minimal underwear relying on washing them in the hotel sink, but this isn’t always convenient or practical. In fact, I recently read a humorous take on packing where the author joked about never needing to wash underwear "in a coffee machine" because they pack like a sane person. While funny, it highlights the importance of packing enough clean clothes to avoid such quirky shortcuts. Another tip is to choose underwear made from quick-dry and breathable fabrics if you want to limit how many pairs you bring. This way, even if you wash a pair overnight, it’ll be ready to wear the next day. Also, organizing underwear by color or type (e.g., black and white socks as mentioned in the OCR content) can help you keep your luggage neat and make packing and unpacking more efficient. Ultimately, the right amount depends on your comfort level, trip activities, and access to laundry facilities. For me, the peace of mind that comes with packing extra pairs outweighs the slight increase in luggage weight. Plus, it's one less thing to worry about during your adventure!