The night before, combine the water, quinoa, oats, and salt in a medium saucepan. Bring to a boil. Reduce heat and simmer, uncovered, for 2 minutes, stirring frequently. Remove from the heat, transfer to a covered container and chill overnight.
In the morning, reheat the cereal in the saucepan on the stove-top. Add the maple syrup. Customize each serving with spices, fruit, and nuts.
Any combination of cinnamon, nutmeg, fresh berries, chopped apple, raisins, dried cranberries, chopped toasted pecans, or walnuts.