How to do tree braids

I've been trying to do tree braids but once I've braided a row what do I do next?  Do I continue in a never ending braid or is each row separate and if so what do I do with the ends of each row?  I also want to know how to do them without bringing them all back.  You know maybe with a part so that it will hang sort of like a bob. Can someone please give me step by step instructions or tell how to get them.