Thanks for all of the replies, the Icing turned out great!
Only my second try at RI on cookies and I know they aren't perfect, but I am happy with them! The christmas jumpers are for a fundraiser at my workplace on Friday and there are some neighbour/friend/teacher gifts too.
Underestimated how much White i would need so making some more up tonight to finish off - hoping for a delivery of brown colouring today to finish the reindeer shapes off too