Add a pinch of salt

You'll probably note that most frosting recipes call for a small quantity of salt when you follow them to prepare your frosting. Some people might be unsure if adding such a tiny quantity will make a difference and decide not to. However, adding salt balances the flavors, thus you should never leave the salt out of sweet foods. Frosting that is either too sweet or not sweet enough can both be fixed with salt.

Even a small amount of salt can improve the flavor of the powdered sugar in the frosting and give it the finishing touch it needs if the frosting tastes good but seems incomplete. This has a similar effect to adding espresso to chocolate treats to enhance the chocolate flavor. On the other hand, if your buttercream is too sweet for you to eat, adding a little salt to taste can help balance everything out and cut the sickly sweetness. So, in any case, adding salt to your icing is your best bet.