I wrap my bags in saran wrap. I know what you mean about consistency though. While piping my icing gets volume/puffs up. I am guessing my hands are too warm. Regardless, I am piping away and suddenly the design is ruined because the icing gets puffy. lol Then I am disheartened. But I keep trying. As for practice, I keep using the icing. lol It's usable, I may have to add more confec sugar or have to stir it back to consistency. It's money spent, so don't toss it.