One year I did something fantastic (which sadly set the bar and has never been matched...all courtesy to Mumsnet.
The whole stocking was themed for DIY and car tinkering. A magnetic underbonnet light. Extendable bendable torch thing. Magnetic wristband to hold screws. Some sort of laser measuring gadget. And then obligatory orange/sweets. Went down an absolute storm. If you look at DH stocking threads maybe 2-3 years ago, you'll see that one.
This year, I've gone with....
3m phone charging cable set because he's always on his phone and the little cables aren't long enough.
Silly socks that read on the sole "if you can read this, bring bacon"
A tape measure, that along with cm and inches, has various bizarre heights marked on it too. Eg "average height of pygmy goat"
A white chocolate orange and some festive chocolate Colon caterpillars.
Fortnum's and mason Lobster bottle opener.
None of which are particularly inspired, or go together, but I'm totally stuck this year, and DH never had a stocking before me, and has really taken to it, so I'm following with interest for some inspiration!