Step 1: Create a Ponytail - To begin, gather your hair into a ponytail at the nape of your neck. Use a throwaway elastic -- one that you can snip away with scissors at the end.
Step 2: Divide Your Ponytail - Next, split your ponytail evenly into two sections. Unlike the classic plait, a fishtail braid only requires two sections.
Step 3: Begin Weaving - Use your finger to separate a small section of your hair from the outer edge near the elastic and cross it over to the opposite side (overlapping just like you would if you were doing a standard braid). Repeat with a small section from the other side.
Step 4: Maintain Evenness - Continue overlapping pieces from both sides of your ponytail, all the way down to your ends. Be sure to pull small sections from underneath to cross over, and try to grab the same size (about a half inch) sections from each side.