I am a US citizen and I am flying to the UK for vacation purposes. I don't plan on making any big purchases, definitely less than $800, but I want to be prepared for how many details I need to keep track of when coming home. If I buy a couple of CD's or books that are less than $10 each, can I just group "CDs" or "Books" on the customs form and put a value of $20? Same idea for souvenirs or clothing purchased. Or is this so little that I shouldn't even be worried?
If I don't get a form (as happened to me coming home from Mexico) and I'm just asked, "Do you have anything to declare?" would I answer yes if it's literally just two books worth $20??