To Eden's list I'd add one brake cable and one derailleur cable and the knowledge to replace them. If a cable should break at the lever (which is where they're most likely to break), it may not be immediately obvious where the new one attaches, so it's best to know this in advance.

The advice Eden gave about headset adjustment really goes for any fasteners - it's just more critical when you're talking about carbon parts. No one's going to advise you to carry a torque wrench on a tour , so you'll need to get a feel for when a fastener is tight enough to hold, and don't tighten past that point.