Please refer to the post on surfactants if the following seems like nonsense to you!
Oily hair: Goal - mild cleansing, degreasing
I usually choose Bioterge 804 and LSB (or DLS Mild) as good cleansers and mild degreasing. I always add a bit of Amphosol CG for more mildness.
Dry hair: Goal - mild cleansing, moisturizing
I'd choose BSB or LSB for mildness, and Amphosol CG to add even more mildness (and it's a humectant, and dry hair can always benefit from some moisture!)
Normal hair: Goal - mild cleansing
How I envy you normal haired people. I'd suggest Amphosol CG for mildness, SLeS for gentle cleansing, and BSB or LSB for mild cleansing.
But like a facial cleanser, the surfactants aren't the end all and be all of the product. We need some good hair loving things in there to make our scalps and tresses feel great! I always add the following
Hydrolyzed protein: You can choose from a number of different hydrolyzed proteins - silk, corn, wheat, soy, oats, and so on. For my coarse, oily hair, I prefer Cromoist, hydrolyzed oat protein. I have found people with dry hair like the silk proteins. Normal people can use whatever they like, but Phytokeratin with soy, wheat, and corn proteins is a lovely choice for almost anyone! Use at 2%. (As this is anecdotal information, try any hydrolyzed protein you like!)
Panthenol: It helps build strong hair and adds Vitamin B5. So we'll want this at 2%. (There is some debate about whether or not this is valuable in a shampoo as it is rinsed off. I figure 2% isn't breaking the bank, so I include it. Feel free to leave it out if you wish.)
Glycerin: It gives us bubbles and is a humectant, so I like to add this at 3 to 5%.
Conditioning agents: 2 in 1 shampoos contain dimethicone, a silicone, as a conditioner. This is a good choice for non-2 in 1 shampoos at 2%. Or you could include something like Condition-eze 7, polyquat 7, at 2 to 3%. This will give you hair a conditioned feel. (We can't use cationics like BTMS or CR well in a shampoo, that's why we're turning to the cationic polymers like the polyquats or silicones, like dimethicone. More about these products in the conditioner post coming up later this week.)
Extracts: You could include something like rosemary extract in your hair. It's supposed to be good for building strong hair.
Essential oils: I love using essential oils in shampoo. For my oily hair, I like to 2% of an oily hair blend (equal parts lemon, rosemary, sage, and cedarwood). For dry hair, 2% equal amounts of geranium, ylang ylang, and lavender can be a good thing. For dandruff-y hair, you might consider using peppermint and tea tree at 1% each (for a total of 2%) in your mixture. And normal haired people can choose whatever they want, including various fragrance oils.
Crothix: For thickening and increasing mildness
There are many different ways to make a shampoo, but I like a 40 to 50% surfactant mix. Again, you can go with 30% or less, but I like my shampoos to be concentrated, so I use more surfactants.
OILY HAIR BASE
15% Bioterge 804
15% DLS Mild or LSB
DRY HAIR BASE
NORMAL HAIR BASE
15% BSB or LSB
FOR ALL HAIR TYPES
10% Amphosol CG (for all hair types)
2% hydrolyzed oat protein
2% dimethicone or condition-eze 7
2% essential oils
(optional) 0.5% extract
up to 2% Crothix
0.5% Germall Plus or 1.0% Germaben II
Colour, if desired
Mix the surfactants together and blend well. Add the water and glycerin and mix well, avoiding bubbles as best you can. Then add all the other ingredients, except the Crothix and extract.
If you wish to add a powdered extract, add it a bit of hot water and stir until dissolved, then add to your mixture.
Add the Crothix after letting the mixture settle and come to room temperature. Start with 1% Crothix, mix well and see if you like the consistency. If you do, let it sit for an hour or so at room temperature to see if it maintains it. If you don't, then add up to 0.5% more, then 0.5% again if you aren't happy with it.
Bottle, name, and enjoy!
A NOTE ON CLARIFYING SHAMPOO: If you are looking for a clarifying shampoo, make up the basic shampoo recipe but leave out the dimethicone or condition-eze 7 as clarifying shampoos DO NOT use any conditioning agents or silicones. I like to use these once in a while. If you want more information on what makes a clarifying shampoo clarifying, check out the post on the beautybrains.com "How Do Clarifying Shampoos Work?" (I love this site! Bookmark it now!)