Does anyone know how to do tree braids by themselves?

[tryn2growmyhair]

I love the ones that DSD has in her album and I was wondering if anyone knows how to do them by themselves.

 

[CurliDiva]

I would love to do these with that very curly hair, but I'm not sure what type of extensions to buy. The human hair (wet N wavy) looks like a looser texture than what I'm aiming for. Any suggestions on brands???