13. If you can swing it, buy one nice, tangible “thing” for yourself while on your trip (and I’m not talking about a random trinket or souvenir with the country’s flag on it). Think of this like a jacket or a pair of shoes or even a cheap pair of earrings. Whenever you use the item, you’ll think, “Oh, these are my London sunglasses” or whatever, and they’ll always have you feeling nostalgic about your trip and ready to book another one.