The secret to crispy potatoes is to cook, cut into small, even cut pieces, toss with oil, and roast at high heat. The best temperature for roasting potatoes is 400 or 425 degrees.   If you want to roast at 450 degrees, keep an eye on the potatoes to prevent them from burning.  Any temperature over 400 degrees is the perfect temperature to cook the potato and get the skins crispy. Of course, every oven is different, so test temperatures to see which one gives you the perfect roasted potatoes.