First, you seperate you're hair into two EQUAL groups.
next you take a small section from the BACK of the left or right stran (or group)
Then, you take another small section from the opisite (other; i spelled tht wrong i know)and cross it to the side you started on.
Repeat this process until you feel like you are done with your braid.
Here is some pictures to help if it got confusing.
here is what your final braid should look like