So, playing TF2 a lot recently

Playing A LOT of spy, Saharan Spy and Dead Ringer is my only real class at the moment. Still <200 hours in TF2, shows how little I used to play it.

Still, a fantastic game. And here's a video of how to play that class properly (i.e. 1:1+ K:D)

So, anyone have tips for playing this class, other than 100+ more practice hours? It's my favourite class by far.