Credit to @sofiastyhorpaylikson for this idea!
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1) Push all hair behind your shoulders. Preferably hair that has already been brushed and has no tangles. Divide hair into two sections down the back.
2) Take a small outer piece of one of the two sections of your hair (it doesn't matter which section you start with). Cross the small piece over and add it to the inside of the other section. This piece you have crossed will now become a part of the other section. Keep your crossed piece tight or hair may start to come out once you've finished braiding.
3) Now you're going to make the exact same cross but this time you will use the other section of hair. So, once again take a small piece from the outer part of the section and cross it over to the inside of the opposite section. Again, remember to keep the crosses tight.
4) Continue crosses small outer pieces over to the inside of the opposing section. The smaller the pieces you cross, the better the braid will end up. Stop braiding once you feel the sections getting too small. This should be around two or three inches from the bottom of you hair.
5) Once you've reached the end of the braid, tie it off with an elastic. Preferably a thin, clear one, but if not any hair tie will work.
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Hope these steps helped some of you achieve a beautiful dovetail braid!