In the steps below, I am detangling my 4c hair-ed daughter's hair. I just discovered that she has very tight coils from the middle of her head to the nape area, and loose coils from middle to her top edges (front).
Here is a picture of her loose coils, which you could say is a 4a/b type.
Step One - Determine what product you will be using to detangle
I do the detangling process during the pre poo treatment time before I wash her hair. Lately, I have used Shea Moisture Organic Raw Shea Butter Deep Treatment Hair Masque mixed with Extra Virgin Olive Oil. You can also just the olive oil by itself.
Step Two - Section hair into four parts
By sectioning the hair into four or more parts, it makes it easier to detangle the hair. It also keeps the detangled sections from being mixed up with the undetangled sections.
Step Three - Spritz hair with water
Undo the section you want to start working with, and spritz hair with some water. Make the hair damp, not dripping wet. After spritz, make sure you massage the water into the scalp and hair.
Step Four - Apply product to hair
Still working with one section, apply the product from Step 1 to a small part of the section portion.
Step Five - Detangling in two directions
This is the starting part of the detangling section. Look at your fingers as the teeth of a REALLY wide tooth comb. Now, start by first combing through the hair with your finger going in an up-down direction.
Then, comb your finger through the hair in a right-left direction.
Here is the detangled section
Now, to keep this section from being tangled up again, I put the hair in two strand twists and secure with a butterfly clip.
Step Six - OPTIONAL Bag it!
Since, we are doing a pre poo treatment, I covered her hair with a plastic cap for at least an hour. You don't have to do this if you do not want to.