In a mixing bowl, take 3/4 cup (173g) of shortening (it can be butter or vegetable shortening, or a mix. The pure butter version, in my opinion, takes away from the ginger flavor a bit, but de gustibus non disputandum est). Cream this until soft, and then add one cup (200g) of granulated sugar, in portions, beating this until you have the usual fluffy mixture. Mix in one large egg, and 3/4 cup molasses (260g) to this, mixing well, and then add the dry ingredient mixture to this, gradually, blending it well.
Here's the only "eyeball" part of the recipe. The mixture at this point will be pretty wet and sticky, so it needs to have some more flour added, so that you can take a ball of the stuff and roll it in your hands without it sticking to you. Around a quarter of a cup (35g) should do it, but determine this empirically.
Heat an oven to 350F (180C, gas mark 4). You'll be forming one-inch (2.5 cm) balls of the batter, and then rolling them in some granulated white sugar on a plate (this makes the cookie surfaces crack in the traditional way). Space them evenly on a sheet (they'll spread) - if you have some baking parchment paper, that's a good surface for them, although they'll usually come off aluminum foil pretty well, too). Bake them for about 10 minutes - the cookies will be slightly domed, and just barely brown around the edges. They'll flatted back out as they cool, and get harder. A ten-minute baking time will leave them somewhat chewy, even after standing, but if you'd like them hard and "snappy", given them another minute or two in the oven, and they'll get there on standing.