Much like making anything in a skillet, do not overcrowd the pan. Use a roasting pan larger than your bird and make sure the sides aren’t too tall. I suggest 2-3 inches tall. If it is any taller, you’ll risk steaming the turkey, which will make the skin soggy (and ruin the crisp!) Also, try to use a raised roasting pan (has a wire insert or large grooves to catch the juices). Keeping it up and out of the liquids will help keep the skin crispy. Do not use a rimmed baking sheet, the turkey will have way more juice than you'll have space for overflow.