When you take your toast out of the toaster and lay it down on your plate to cool, moisture can seep back into the toast, causing one side to become soggy.
Fortunately, there's a way to prevent this. Take the toasted slices of bread, stand them up, and balance them against each other so that they resemble the sides of a tent.
Balancing the two slices prevents condensation from building up and allows for free airflow so the bread can cool down without trapping any heat underneath.
It may also be worthwhile to invest in a toast rack. For one or two pieces of bread, save your money and stand your bread up on one edge to prevent it from getting soggy.