>>212730453 (OP)I remember learning to whistle. At first I whistled through my teeth. But this is wrong; you should whistle by rounding your lips and blowing air through them like you would an instrument. Whistling should take up your whole mouth and the breath control is a lot like playing a woodwind instrument.
I'm an adult now. My friend asked me how to whistle and I told him to do this, and to just keep trying over and over again. He wasn't satisfied by this and still can't whistle.
You can try this and see if you're more successful.