I don't do a stocking for mine but I'm looking for inspiration.
Mine have a Dec 1st Bag so the underwear, robes, pyjamas (winter not Christmas) socks go in that .
I got her a Sock advent calendar last year
DD has a Beauty Advent Calendar that I make up for her , so all the skincare , shampoo, make-up , lipbalm , hand+foot masks in that .
I try to keep it under £5 /day . Some 3for 2 , some travel kits I split up .
They do have gorgeous tapestry stockings with lights
that I put their presents in , their presents tend to be tiny and £ now .
(The bags , advent wrapping and stockings are re-used)
DS likes money so a gift wallet with cash or a "We've transfered £X to your account"
Things for his guitar ( he was 21 last year so got a 21st/Christmas combined Fender stratocaster , amp and various bits )
Lindt chocolate teddy bears or reindeer
Extra long charger cables
Mine wouldn't use Costa or Starbucks gift cards , I think they use ApplePay for that
No candles , the female cat likes DD room and she'd knock it over
Jewellry would go in her main presents
Alcohol miniature as a table gift