Stab it all over with a fork.
Sprinkle some salt and pepper (It will make skin crispy)
Get the oven nice and hot - 220 C is about as hot as mine will go.
Place the potato on a baking tray, and bake for ~1 hour, turning over half way through.
Hold the potato in a clean tea towel, and give it a good, firm whack on the work top. This breaks up the skin a bit, and somehow makes it go all fluffy and light inside.
Split the potato - split it along the top, then press from either end of the split to spread it out and up.
Add a generous knob of butter.
And finish with your favourite topping! Here is the classic beans and cheese. Yum!