Homemade frosting recipe:
mix 1 cup shortening with 1 tablespoon vanilla, and 1 tsp imitation almond
mix together till blended
mix in 2 tablespoons water
mix in 4 cups confectioners sugar (mix in 1 cup at a time, mixing between each cup with an electric mixer).
Add 1 tsp of water at a time until desired consistency, don't add a lot of water at once, will get very thin very fast. Heat and humidity in mind, make it firmer if its warmer.
Put into bag and pipe or use a spatula to frost.
Since no butter or milk, this doesn't need to be refrigerated and lasts a while! I make about 400 cupcakes a month with this recipe, and I'm told it's well liked. Add your coloring last. If you want true red or black frosting, you put your color in, mix it in, and leave it overnight out of the sun, the color will deepen with time.
Good luck!