Take a look a video I made with my son Mateo, teaching to make a Flute.

Lesson One: Blowing the side blown flute
1)Hold flute near mouthpiece keeping all finger holes open.
2) Find Hole with tongue
3)Press flute against SOFT relaxed grin.
4)Roll flute a bit and blow while grinning.
5)Pretend you are spitting out watermelon seeds.
6)Beware if you pucker you get dizzy, and the air will not split across the hole correctly.
This is the hardest trial in flute playing. If you don't succeed the first time, well, try again!
7)Look into the mirror and form your lips to make a line and not a hole. Press flute and roll.
8)Try saying the word “Tooty Too” for a bit and the word “Pure”.
9)Make sure your lower lip is not tight but relaxed