Preheat oven to 400°F (200°C)
Scrub potatoes clean and dry them
Pierce potatoes with a fork
Bake potatoes directly on the oven rack until tender, about 45 to 60 minutes
Let potatoes cool slightly
Cut potatoes in half lengthwise
Scoop out most of the flesh, leaving a thin layer inside the skin
Brush skins with melted butter or oil
Season with salt and pepper
Place skins cut-side up on a baking sheet
Bake again until crisp, about 10 to 15 minutes
Add desired toppings
Bake a few more minutes until toppings are heated through