I would put Market cotton scarf from Peru on the list for Peru because it is the kind of thing that feels useful once you are home, not just another airport purchase. I would avoid the obvious tourist print and look for something with a local pattern, fabric or cut that still works with normal clothes back in the UK. I would look for it in a proper local supermarket, covered market, deli, pharmacy, gift shop or small producer rather than leaving it until the departure gate. Back in the UK, it is worth checking specialist shops first because they often stock a better version than a broad marketplace listing. The reason it works is that it gives you a quick reminder of the trip without needing to keep a fragile ornament safe forever.