Shortcrust pastry is easy to make. It’s a very simple ratio.
Measure out some self-raising flour.
Measure out half the amount of the self-raising flour with fat (lard, cooking margarine etc)
Measure out half the amount of fat with water.
Eg. 300g Flour, 150g fat, 75g water.
Simply mix the flour and fat with your finger tips until you get crumbs. Add the water until it becomes a dough. The world is then your oyster. Make whatever you like out of it.