Have you thought about using the Design of Experiment (DOE) technique, but dropped the idea due to lack of learning time? Now you can apply the powerful DOE technique for many simple experimental situations without worrying about the math behind it.
You can use Easy-DOE to OPTIMIZE any process (CAKE BAKING, PRINT/WEB Ads, MACHINING, STAMPING, Etc.) or investigate & SOLVE PROBLEMS. After you describe how you measure the results and identify the process parameters (Factors), Easy-DOE will DESIGN EXPERIMENTS and prescribe the recipe for you. Upon running the 8 experiments and inputting the results, Easy-DOE analyzes results and determines the best solution (optimum condition).