Colourful Andean woven pouch or cloth inspired by traditional aguayo patterns.
This is exactly the sort of thing I like bringing back from Bolivia: small enough to fit in a bag, but specific enough to remind you where you bought it. 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. 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.
I would put Bolivian quinoa on the list for Bolivia 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.
When I think of an easy, crowd-pleasing thing to bring back from Bolivia, singani grape spirit is a good pick because it does not need much explanation when you hand it over. For alcohol, I would only bring this back if it is sealed properly and comfortably within the UK allowance; otherwise it is better as a UK-buy link. 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.
Ají amarillo paste is worth adding because it feels like something you actually noticed while travelling through Bolivia, rather than a generic souvenir. 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. The ideal version is modestly priced, not too bulky, and good enough that you would buy it again even without the holiday memory.