My mom took a Wilton cake decorating class at Sears when I was just a toddler and she honed her skills in the 27+ years since. She makes her own buttercream frosting for everything – 1 box of confectioner’s sugar, one stick of room temp butter, 3 tablespoons water or milk and 1/2 tsp each of butter, vanilla and almond extracts.

For smooth icing she does the following:
1. glazes the cake first with a water/icing mixture
2. lets that harden completely
3. ices the cake using metal icing spatulas (the kind that are bent just at the base; she never used a straight spatula) that have been hanging out in a glass of warm water, changing frequently and shaking off the excess water as needed

I know that’s a bit unsolicited, and I can’t pipe much of anything myself despite my years of “apprenticeship”, but I do know the warm water trick works!