The way I do em is: cut a cross on the tops, about 1/4 inch deep.
Micro wave for 10 minutes.
Then put in a preheated conventional oven for the remaining 20 minutes.
Cheese and beans are my fav toppings.
If you want to them in the bonfire, prepare the spuds with slits, as before and place them in an old biscuit tin with a few holes punched in the lid.
Put the tin in the base of the fire, when you have a good layer of embers and leave to cook for at least an hour (a bit more hap hazard) but you have to use your own judgment) you may find a shovel handy for placing and retrieving the tin. Works for me anyway.