The air fryer itself already does a lot of the heavy lifting in crisping foods, due to the hot circulating air. In addition, you can also use these techniques to boost up the crispiness factor of your air fried fingerling potatoes: -make sure the potatoes are dry (this is why I recommend blotting the cut sides of the potatoes); -use a generous coating of oil; -spread the potatoes out evenly (don't pile them on top of each other); and -enjoy the potatoes right away! They will get softer the longer they sit out.