I have vivid memories of learning to whistle when I was about 5 years old. I walked about for days on end with my lips puckered, blowing like mad, until the day came when a soft whistle emerged and I was soon whistling like crazy. Some years later I started to practise whistling with 2 fingers in my mouth. It took time but I got there.
There's only one answer - persevere. As Lauren Bacall said, "You know how to whistle, don't you Steve? You just put your lips together and blow".
