Fresh strawberries provide the best flavor and texture.
Make sure your baking powder is fresh. If your waffles are flat, it could be old baking powder causing the issue.
Stand close to the waffle iron to keep track of cooking time. If you lose track of time, you could end up burning the waffles.
Store the leftovers in the fridge in an airtight container for 2-3 days, or freeze for up to 3 months.