On my last tour, my front tire got gashed, causing the tube to blow out. Luckily, I carry tire boots (plastic rectangles with stickem on one side), which I hadn't used before, for just this problem.

I was able to ride another 200 miles on the booted tire without having to replace it!

I agree with both of the other responders: make sure you know how to use the tools you bring.

For me, I bring multitool (Allen wrenches, chain breaker, screwdrivers), Leatherman Juice (knife, screwdrivers, scissors, pliers, can opener), metal tire levers, tire boots, patch kit, hypercracker (lock ring remover), spokes, fiberfix temp spoke, spoke wrench, S&S coupler/pedal wrench.

I also carry a replacement bolt for every one I have on my bike (I did this after breaking the seat clamp bolt), a few extra chain links, and chain pins.

For more discussion on this topic, this page has 5 links about tools to take on a bike tour.

Ray