We don't eat many mince pies, so it's not worth making my own mincemeat. This year, I used a Cranberry and Port Mincemeat from Waitrose; a pretty dark red colour and plenty of flavour.
I use my own pastry recipe, a combination of how my mother makes all her pastry and a sweet shortcrust. My mother uses SR flour all the time - it makes the pastry short and crumbly, and prevents it hardening after a few days, as regular shortcrust pastry can, especially if you're not an expert, and are a bit heavy handed with the water. I find using SR flour especially useful with mince pies which you want to keep for quite a while. This amount of pastry should make about 2 dozen pies.
500g SR flour, 250g salted butter, rubbed in. Sift in about 75g icing sugar, and mix to a dough with a whole egg and as much cold water as necessary. The dough should be a smooth paste which holds together well but isn't too wet, or crumbly around the edges - unfortunately only experience can help you with this! Knead lightly and chill for 20 minutes. Divide the dough into quarters, for ease of use. Roll out one portion and cut out an equal number of pie bottoms and lids to fit your moulds. Add the trimmings to the next portion when rolling those out. Assemble pies as usual and bake at 200C until golden - could be anything from 10 to 20 minutes, depending on size of pie and thickness of pastry.
My mother always brushes the pastry lid with water and sprinkles over some granulated sugar before baking, and this is a tradition I carry on - I like a sparkly finish better than a loose dusting of icing sugar afterwards. I only had caster sugar available this year, which doesn't work quite as well, because of the smaller crystals.