Add your rolled oats to a large 8oz glass jar or container. If you're using flax or chia seeds stir them into the oats.
Add the optional maple syrup (or sweetener of your choice), pour in the water or milk, and mix well.
Cover with a lid or wrap and place in the fridge for at least 4 hours (overnight is better).
When ready, eat with your favorite toppings (see recipes and suggestions below).