Peru
This is exactly the sort of thing I like bringing back from Peru: small enough to fit in a bag, but specific enough to remind you where you bought it. The best version is usually the sealed jar, tin or packet from a normal supermarket, spice stall or food hall, not the most expensive tourist version. It is also the kind of thing you can talk about when someone asks what you brought back, because there is usually a little story attached to where you found it.
Peru
When I think of an easy, crowd-pleasing thing to bring back from Peru, alpaca scarf is a good pick because it does not need much explanation when you hand it over. 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 rate it higher when it is locally made, clearly labelled and easy to use at home, and lower when it is just tourist packaging.
Peru
I would put Peruvian quinoa on the list for Peru because it is the kind of thing that feels useful once you are home, not just another airport purchase. Grains, pasta and rice are not glamorous, but they are useful, cheap and often taste different from the UK supermarket version. The reason it works is that it gives you a quick reminder of the trip without needing to keep a fragile ornament safe forever.
Peru
Grape brandy used in pisco sours and other cocktails.