My question : what ingredients do you use (other than oils and fragrance) and why?
I'm in the same boat - been experimenting like crazy! So far I have done:
liquid subs:
coffee. I brewed at double strength, used for 2 different style bars and they both smell like heaven! I've read that coffee is great for skin conditions, although it's debated how much of the good stuff survives saponification.
apple cider. Does not make your soap smell like apples btw. I had this in the fridge so... why not make soap out of it?
coconut milk. Love this for moisturizing. Although my next go round with it I am going to reduce my CO by 5% to get more moisturizing out of the milk.
And I have aloe vera juice to try out as soon as my new NaOH order gets here.
A few experiments still on my cure rack:
ground lavender buds with kaolin clay (oddly the ground buds are not turning black - I ground them with the clay so I don't know if that's holding them or they just need more cure or I'm color blind...) I made this for my pastor's wife who loves lavender and wanted an exfoliating bar too.
Colloidal Oatmeal: doing an exfoliating material comparison.
Coffee Grounds: see above exfoliating experiments and coffee notes.
I always add some kind of clay to my soap (1TBSP PPO), but I'm experimenting at the moment with different methods of adding it, such as putting it in the lye water (pre adding the lye) and straining before adding oils, or adding 2x or 3x for color and slip comparison. I haven't used charcoal yet, but I'm on the hunt for it in my local stores. I also have adding salt to my bars on my experiment list (for a harder bar).