idiot question - icing

[StealthPolarBear]

made icing (for christmas tree shortbread), how do i make it so it'll set on the biscuits? it's sloppy at the moment

Add loads more icing sugar. It sounds like you have added too much water. You need almost no water!

thanks - thought that might be it!
Just wanted to check it wasn't some magic ingredient that I didn't have