Well, I must be an old'n because I know the answer to this one!
(ahem...my name...)
I never make less at one time...this will make a large batch. Probably about 6 cups...you may cut it in 1/2. BC keeps in the fridge for a long time. I used to keep some of each color in the fridge when I decoroated all the time.
1 cup of Crisco
1 cup of butter
1 2-pound bag of confectioners' sugar (or powdered sugar/icing sugar)
1 tsp vanilla flavoring (use clear if you need WHITE icing)
I do not use stick butter in mine. It is harder to work with and will make your icing more yellow or ivory. Some recipes tell you to use a couple tbsp of milk, but I do not. If I need it thinned down more, I use more vanilla!
I hope you have a stand mixer. This stuff is really hard on hand mixers. If you make a lot of it, it will eventually burn up a hand mixer. I've made probably tons of this stuff.
Beat the butter and Crisco until blended, add vanilla, mix. Gradually add the sugar, about a cup at a time. beat until you reach your desired consistency.
Now, get creative! I add the LorAnn flavorings, most popularly known as the flavoring for hard-tack candy....YUM! Any flavorings will work, but more concentrated ones are better because you don't want to thin your icing too much. I really like the strawberry added into the buttercream.
If you want to tint the icing, I use the paste food colors. If wanting a deep red, it's best to tint it and let it set overnight in fridge bc the color will deepen as it sets.
I have also added a packet of Kool-Aid to help achieve the red colors and everyone seems to go crazy over the amazing flavor! It's really good.