I use a recipe from Ireland's Ballymaloe Cookery School. It's 1 pound of flour, 1/2 tsp of baking soda, 1/2 tsp of salt and 1 tsp of sugar sifted together. I make a well in the center of the dry ingredients and pour in about 14 ounces of buttermilk and mix the dough together very lightly with an open hand so not to compact the dough. the dough is turned out on a board every so briefly just to be patted together and then, when formed into about a 12" placed on a baking sheet. I cut a deep cross in the dough, as they say, to let the Faeries out.
We have a cupboard full of marmalade, just waiting for soda bread toast.