DIY- How to Curl Your Hair Using a Flat Iron

It's been a year I let my hair grows long and kept the hair style just like that (straight to the end) and there nothing more I do than just make a poni tail or pull them up like a bun.

Bore with it, I went up to salon and got my hair done (smoothing and layering) . Yess, of course I was satisfy with the result

, but all the hair done goes straight again after I wash my hair :"( just like this:

I really want that waves back... but since I don't have any curling iron, So I browse how to DIY - Curling or just add some waves to my hair using flat iron (hair straightener)on youtube, and VOILA!!! I found it.. there are many of them but I reference this ONE because she has a long hair just like mine.
and here the result:

sorry for the low quality picture :p