I buy the best trailer tires I can, I have two spares. I hate damn flats. I keep a good high lift jack, lug wrench, hydraulic jack, four way lug wrench and gloves with me, just in case!
As an aside to spare tires and the chore of changing a tire on a trailer or truck. I've started to carry a Dewalt 1/2" electric impact wrench when I travel. Hope I don't need it but if I do I'm gonna change a tire like NASCAR fast.