Pre-heat the oven to 170 degrees centigrade fan oven
Add the flour to the butter and cut the butter into little pieces
Add the caster sugar to the mixture and use the rubbing in method until fine breadcrumbs
Add any flavourings you want (choc chips) and continue rubbing in until clumps together
Roll out onto a floured surface and roll until 3/4 of a centimetre then proceed to cut into small pieces and put onto a baking tray
Cook for 10 minutes or until golden brown