I practise every day when I go outside with my dog. I figure the neighbors will think I’m whistling for my dog and not some crazy old lady that just whistles. lol!
I can usually get a fairly loud whistle by the third try. But it isn’t as loud as I want. My goal is to be able to whistle loud enough to stop a taxi cab. I don’t live anywhere near a place with taxi service but someday I might need this skill.