I followed many how to's on the internet, and watched a few you tube videos. I found the best directions were the ones that you hand written as opposed to a video.This website on how to make a clay whistle is great! It even gave me an insight to what was going wrong when my whistle didn't whistle right.
I started doing the whistles as a challenge when I took a ceramic class just because. I used to be a potter by trade many moons ago and just wanted a refresher course to get my juices flowing. Making clay whistles isn't for everyone, but I get a kick out of making them. It is challenging as you have to get the main hole just right.
My snail whistle is now selling on Etsy. Just click on "snail whistle" that is highlighted and it will take you to my shop. And just so you can enjoy it here, here is a few of the pictures of my little ocarina here.
You can always visit my shop for more silly whimsical useful ceramics.