Their favourite chocolates/biscuits, favourite tea or coffee. If they drink some of their favourite drink, nice cup or glass, small Christmas pudding each (if they like), tote socks, hand creams, puzzle books or game they would enjoy, maybe quiz related or if they like criminal shows you can get detective solve crime games.
Last year I did my in-laws one each, I adapted each to suite personalities. Mil got bottle of gin, gin cocktails book, gin glass, scented candle, nice chocolates, gloves, toy for her dog. FIL was nice mug matching mils gin glass, he dosnt drink, hence the mug, his favourite tea bags, favourite socks, sudoku book, favourite biscuits, portable charger pack, toy for his dog.
I always find hampers are better with things the person actually likes rather than fancy things that may look or sound nice, but you can never be sure they will actually use what’s in them. We do my DHs aunt one every year, it’s filled with all her favourite things, cappuccino sachets, kitkats, french fancies etc… the one difference we add is what ever Xmas themed gift we put in it, this year a nice bauble. She looks forward to it. She has no problem telling us if there is something she dosnt like, hence us knowing exactly what to put in.