Most Helpful Guy
First make sure you're using a good waffle batter and not pancake batter as waffle batter has more sugar for caramelization and more fat/butter/oil for a crispy exterior. To keep them warm and crispy heat your oven to 200F and place your waffles directly on the baking rack so your waffles stay warm and crispy and don't get soggy as they continue to release steam.
Most Helpful Girl
Eat them asap as soon as they are done cooking