part 1), potential recipes for dry skin (part 2), and potential recipes for oily skin (part 3), let's take a look at normal skin and a few tweaks you could make to this product. I think this is the kind of product that is all about individualizing the product for your skin type, so be prepared to make small amounts and keep loads of notes!
What oils might be good for normal skin? If you have normal skin, you will want to use 25% to 50% castor oil - depending upon what level you find drying or over-cleansing - and the rest in pretty much any oil you want. If your skin tends to feel drier, then I suggest using less castor oil and more of the oils for dry skin. If your skin tends to be oilier, then I suggest using more castor oil and more of the oils for oily skin.
Sorry for being so vague here, but I haven't tried making this product for all these different skin types. I'm going by the information I know about oils and the feedback I've read in the Dish forums about various combinations. The reality is that you could have really dry skin and use 50% castor oil because we all know our skin never ever goes by what is suggested for it! As with every product we make, be prepared to make all kinds of tweaks based on what you have in your workshop, what works for your budget, and what your skin likes!
Cromollient SCE (seems like the most popular one), polysorbate 20 or polysorbate 80, PEG-7 esters, or emulsifying waxes of all kinds. I've also seen the suggestion to use lecithin. The basic idea is to use something that will emulsify or solubilize the oils. It will remove more oil from your skin and apparently leaves behind less mess in your sink or wash cloth. Suggested rates were 5% to 10% for Cromollient SCE, up to 10% for polysorbate 20 or 80 (I'd go with 80), up to 10% PEG-7 olivate, or up to 10% for emulsifying waxes. Using emulsifying waxes will thicken the product slightly or even thicken it quite a lot, depending upon how much you use. (I'd start with 2% to 3% and go up from there.)
I've also seen the suggestion to use a lotion as a cleanser. This sounds like an interesting idea as well. The general idea is to apply a lotion, then remove it without water to leave behind a lotion-y moisturization. It sounds like you could use any lotion to do this, but here's a link to a duplicated product called a cleansing milk that works quite well.
Well, that was fun! Thanks for asking the question, Lauren!