I found this article the other day, which goes over some interesting vocal techniques and links for other tips. DISCLAIMER: I have not read through all of the tips on this website and so cannot confirm their validity or safety. I do not recommend allowing a student (especially a young student) to navigate the page alone. Some of the things recommended are things that should be tried once to see how it affects the voice, so you do want to be sure that your students understand that not everything listed is meant to be all the time or for every style of music.
I know it’s been a while…sorry about that! I’ve been focusing on other projects including a novel, my YouTube channel, wind symphony rehearsal, and other elements related to teaching private lessons. Follow me on Twitter, if you like, click here for Twitter and click here to go to my most recent YouTube video. Be forewarned, some (not all, or even a large percentage) of my Twitter and YouTube content is political or social commentary. I tend to lean more toward the right, but have somewhat of a libertarian view (you do you, boo). My greatest goal is to be fair and honest in addressing things that I see happening in the world, hence the screen name. Most of what I post on Twitter is related to writing and research, networking with other writers, etc.
I hope your school year started out well and that you all will have a lovely and music-filled day!