So I've been doing a lot of baking with short-crust pastry lately, with just the last four days alone involving both quiches and enpanadas, and I've gotten to the point where I can make it pretty well purely by feel. It's fun stuff. It's also a lot easier once I learnt you can ignore the traditional way of making it where you aren't allowed to mix the dough too much (lest you homogenise the butter and flour too much), and instead mix the everloving crap out of it, then just relayer it using dry flour to seperate the layers.
Works better, is easier, and you can exactly control how flaky you want it.
Simply do half butter, by weight, to flour (edit to clarify, that's 1:2 butter:flour). Generally, they recommend you use unsalted butter and then salt to taste, but I find regular salted butter is fine; add sugar if doing a dessert dish as well. If you're vegan, vegetable shortening should work in an equivalent role, same ratio. Cube the butter up as small as is practical for you, then mix it in to the flour. If you have a food processor, blend till it looks like coarse, lumpy beach sand. If not, mix it by hand until the same, making sure to break up the individual cubes of butter completely.
Next, add a drizzle of cold water, slowly adding more while working the pastry until it comes together into a single ball. Now roll it out, lightly sift dry flour over the surface, and fold in half. Roll it out again, and repeat. I generally roll it between two sheets of cling film, as it makes it easier to flip and rotate the pastry without it sticking to the table. If you keep doing this, you end up with heavily layered, melt-in-your-mouth-tender, flaky pastry, utterly perfect for things like quiche.