I've often been asked what is the greatest difference in conducting between levels of proficiency. I have conducted groups from Elementary Schools, Middle and High Schools, College level, and up to professionals in film studio recordings. The greatest difference? Attention to dynamics! There is a sliding scale moving from one level to the next, with professionals having the most exaggerated and yet controlled dynamic contrasts. Even college and semi-pro groups are a step down when it comes to crescendos, diminuendos, fortes, and pianissimos.
It's a great idea to teach at the earliest stages of music education. I constantly tell my students that we live in times where music is constant and compressed. Earbuds and loud rock music make everything sound dynamically the same. We have to break that monotony! Dynamics are one of the very best ways to connect, move, and excite our audiences!
The recorder offers us as educators a few ways to instill dynamic contrasts from the beginning. I tell our students to over exaggerate their louds and softs, because what they believe may be a true forte or piano, may really only be a fraction of what the listener hears. I teach them about the "force field," which is an imaginary net between the students and the audience which will swallow up all their dynamics if they aren't loud or soft enough. Tell your students to concentrate on making their air travel faster or slower through the recorder to help in making true dynamic variations.
Here is a great 5 minute lesson plan on dynamics using Go for the Gold Recorder (Beginner's Edition).