... he's going to need fort-building abilities where you use twigs and your sleds to reinforce the walls, sloppy snowball attacks, larger snowball rolling, fort-buster snowballs that take two people to lift, and pre-prepared machine gun snowballs in his kit. And hot cocoa afterwards. With marshmallows that sadly melt by the time you can drink it.
The nostalgia :D
Edit: Oh, and playing dirty by putting snow into your opponent's jacket.