We usually first introduce young people to double reeds since the Crumhorn and Dulcian are both double reed instruments. Reeds are easy to create if you have a simple drinking straw. Here's a fun craft project for young people interested in musical instruments.
Take a straw, cut one end like the picture below, and hold the straw in your mouth two to three inches down the straw. Blow forcefully so that the two sids of the reed buzz. Add holes in the straw to create pitches!