The first thing I practiced was changing TT tires. I used to use a jack on the frame, now I have a tire-aid ramp.
Besides the spare tire, I also carry a small 120 volt air compressor, torque wrench, and anything else I need to get going in an annoying 20 minutes; rather than wait for road service to find me.
So far I have changed tires on the TT twice and TV three times. All were nails or small metal shards. Finally I hit a road hazard that bent the rim and axle, shredded the tire and broke a spring. That one needed road service.
My toolbox is the same one I use at home.