How do I modify a recipe when I add or remove an ingredient?

Let’s take a look today at altering recipes as there have been a lot of questions about this lately. (Original post can be found here…) Let’s say I have this recipe from this post:SWIFT’S BASIC HAND LOTION FORMULA69.5% water15% oil5% butter3% cetyl alcohol or stearic acid6% Polawax1% fragrance oil0.5% liquid Germall PlusPlease use the general…