MandS have some nice small bits, mind games and things. Or nice chocs there or Thorntons.
Taster sizes of interesting whiskey, brandy, etc. or a Christmas beer or 2.
I got a water bottle carrier you screw on instead of bought top and can then clip to your backpack for adventures types (got in great outdoors but try general putdoor adventure shops, shaped like a bird).
Little dainty notebooks for handbags.
Pocket packs of tissues with nice designs on them.
Handbag mirror, nail file, nice tweezers etc - can get some lovely designs still in that price range.
Nice pens in Muji. In fact, lots of nice things in Muji.
Taster packs of different types of coffee beans, or herbal teas.