Here are some of the tips I use when cooking potatoes. If I am need to bake potatoes fast I precook then in boiling water for about 10 or 15 minutes. I coat them with cooking oil before placing on a roasting dish. It reduces the baking time to less than ten minutes.
Another trick is to put a metal skewer through the potato. The skewer acts as a heat conductor that delivers heat to the centre of the potato.