Before Shampoo....
you can do a Pre-Shampoo Treatments (aka pre-poo). Saturating your hair with moisture before you shampoo adds a layer of "protection" from the cleansing ingredients (sulfates and EDTA) in your shampoo. The theory is that the shampoo will be working hard to remove the newly added moisture and it won't be able to strip our hair of all of its moisture that is stored deep within the hair shaft. Essentially, it prevents the striped or "too clean" feeling that we can get from using certain types of shampoos (clarifying and sulfate containing shampoos). The most popular are Hot Oil Treatments, Deep Conditioning Treatments and Instant Conditioner (sometimes mixed with oils).
After Shampoo...
the cleansing ingredients have removed the moisture and "dirt" from your hair. Now that you are left with a clean palette, this would be the best time to incorporate moisture.
Deep Conditioning Treatments, Instant Conditioners, and/or Leave-in Treatments are best suited for this task. Depending upon what you feel your hair needs you can use one, two or all three.
In Between Wash/Shampoo Days...
you may feel that your hair is drying out. To address that you can add moisture without having to shampoo by conditioner washing (co-washing) or using a hair moisturizer. To conditioner wash (co-wash) is to saturate your hair with a conditioner (instant or deep) and rinse without using a shampoo. Hair Moisturizers (you can also use a leave-in treatment for this) are products that you add to your hair without adding water. You simply apply as needed between your wash days. For some that's daily for others it's not at all.
How I Add Moisture
In the warmer months, I deep condition and use a leave-in treatment on wash/shampoo days (once a week). In the colder months when the air is dryer (December to February here in North Carolina), I pre-poo with a hot oil, deep condition, use a leave-in treatment and I may use a hair moisturizer mid week, if my hair feels dry.
Currently In My Hair Stash
Moisturizing Deep Conditioners
GVP Conditioning Balm (Matrix Biolage)
GVP Moisturizing Conditioner (Nexxus Humectress)
Darcey's Botanical Pumpkin Seed Conditioner
Moisturizing Instant Conditioners
None
Moisturizing Leave-in Treatments/Hair Moisturizers
GVP Conditioner (Paul Mitchell) Leave-in Treatment
Elasta QP Moisture Recovery Oil Moisturizer
Hawaiian Silky 14n1 Miracle Worker Moisturizer
Darcey's Botanicals Lemongrass Transitioning Creme