I'm working on a shaving soap for my son. The part I'm having trouble with is lather and longevity. I know vitamin E oil will help with the longevity part as will citric acid if I choose to add it. I'm using shea/cocoa butter/coconut oil/avacado oil and additional stearic acid. I'm considering adding palm kernal oil and castor oil. I just don't want to end up with a bubbly soap. I want a rich, creamy, lather with a nice glide from a very hard, long lasting bar. I don't have my percentages set in stone yet so I can't provide a recipe. Suggestions? I need to work with one lye. I prefer Sodium Hydroxide for solid soaps.