Good to hear you like that approach - I'm working alongside an instructor/trainer all summer and slowly taking over teaching responsibilities for the classes. Just looking for any external resources others found helpful! I'm trying to get a variety of perspectives on teaching/presenting skills, since everyone tends to have their own style within the bounds of the standards
Don't get stuck trying to emulate other people's styles. As a DM I'm sure that you have your own way of communicating and getting information across.
That's how you should teach. Don't try to copy others, even if it's inadvertent. If it's not your style it will show loud and clear. It's likely the students will pick up on that and wonder why it sounds like you are parroting information instead of putting it in your own words.
Some people are great at presenting with visual aids like power point. Others should never get near one. I create a lot of power points so I know how to present with them. They are an aid, not a substitute for actually talking and knowing your subject.
I have had instructors that did not use a single visual aid (other than their hands) and it was crystal clear what the lesson was.
If you are passionate about certain subjects, try to tamp that passion a tad. It's very easy to get carried away and spend the entire lecture session on one point that in the big scheme of things is a minor issue. Save that talk for the restaurant or pub after class.
Get intimately familiar with subjects you are not passionate about. Those are the ones that will trip you up.
And the biggest thing I tell DM's working towards instructor, if you haven't done it yet, take a couple tech classes from a tech instructor other than your DM instructor. At a minimum, Intro to Tech and Advanced Nitrox.
Not only for the knowledge and different teaching perspective, but to get a taste of what diving really is and how it is an extreme activity that can and does kill people. Even at the OW and even Intro to Scuba levels if the instructor is not on their game or the student doesn't seem to be taking things seriously.
I am retiring from teaching but I have told every student the same thing, before they signed anything or I took payment from them.
"Scuba is fun, exciting, educational, relaxing, informative, and, if done within the limits of ones training and experience, it can be safe. But make no mistake, you are entering an alien environment that is normally hostile to human life. Try to go beyond your training too far and too fast, or get complacent, and it will kill you in some very nasty and creative ways. What we are going to do in this class is try to mitigate that risk. The only way to eliminate is not to dive, but, we can reduce the chance of you becoming a statistic."
That never scared away a student, but it made sure I had their full attention from day one.