The essential technique here is to rub the fat into the flour until evenly distributed - stop rubbing when the mixture resembles fine breadcrumbs.
Rub the butter into the flour between your fingers and thumbs. Lift your hands up out of the bowl as you rub. This will incorporate air into the mixture.
Add the sugar and mixed dried fruits and stir until all of the ingredients are evenly mixed.
After adding the egg and milk, incorporate the flour from the sides gradually and mix together well.