I used to do cake decorating, just for friends, even wedding cakes with intricate patterns & lacework. Other than the wedding cakes (which were done with royal icing, I always made the Wilton "buttercream recipe", using Crisco shortening. I'm not a Crisco fan for any other purpose, but in my experience it gives the best consistency and is pure white, so your icing is truly white and your blue icing doesn't turn greenish from the yellow of the butter. It's also very stable in warm summer temperatures and lasts pretty much forever. When you're done practising just scrape it off the tray, put it in a good quality freezer bag and put in the fridge; I used to keep mine in the back of the veggie drawer. Remember to take it out the day before and you'll need to use the mixer on it to bring it back to a good texture; may need a tablespoon of milk or corn syrup if it has dried a bit. Good luck with your practice!

I used to do cake decorating, just for friends, even wedding cakes with intricate patterns and lacework. Other than the wedding cakes (which were done with royal icing), I always made the Wilton "buttercream recipe", using Crisco shortening. I'm not a Crisco fan for any other purpose, but in my experience it gives the best consistency and is pure white, so your icing is truly white and your blue icing doesn't turn greenish from the yellow of the butter. It's also very stable in warm summer temperatures and lasts pretty much forever.

When you're done practising just scrape it off the tray, put it in a good quality freezer bag and put in the fridge; I used to keep mine in the back of the veggie drawer. Remember to take it out the day before and you'll need to use the mixer on it to bring it back to a good texture; may need a tablespoon of milk or corn syrup if it has dried a bit. Good luck with your practice!