Try rinsing your teeth with water directly after eating. This will help rinse off the bacteria in your mouth that produces acid that can temporarily weaken your enamel.
You don't need to think too hard on this one, a quick rinse with water will boost your body's ability to clean itself and remove any food or sugar that's leftover. Of course it doesn't remove it all, but that's why we brush and floss too.
A quick note on mouth wash — A common misperception people think they can get away with is, substituting mouthwash for brushing and flossing. Mouthwash is not a substitute! It helps to freshen your breath, but it won't protect your teeth from cavities and gum disease they way a toothpaste and floss do.