Once you started to mix fresh cosmetics home, there is no much limit to what you can do. All you need to know is how every ingredient works in that formula, what are its characteristics and its function. For example, do you use vitamin E to nourish the skin or as a natural preservative? Do you use the wax to enhance the texture of the product or do you need its pale hue for coloring?
Some recipe tweaking is easy - you add more liquid oils or remove some waxes to a lip balm will become softer for easier application using the finger. But with some ingredients you need to be careful, since they should not be used above a certain percentage (or wouldn’t be effective in less than a certain percentage), such as Hyaluronic Acid.
Other tweaking takes time to master. such is the case with colored cosmetics - it takes a lot of experimentation to reach that hue you had in your mind. You will probably create many other wonderful hues on the way - so keep those tiny storage jars in reach.