I used to take a pair of plimsolls, tackies or whatever people call them. Or a pair of light Keen sandals. Although, I have been known not to take any other shoes apart from my Shimano MT91's. Ever since I did my Dungeness to Durness trip when, as I dozed outside my tent in the evening sunshine in a field near Spalding (exotic, I know) a fox ran off with one of my nice little sandals. Managed the rest of the 1800 miles (I rarely take a direct route, in case you're wondering) with just the boots. Even if they were a bit ripe by the time I got home.