1) Take the NRA Certified Instructor course...take three different ones on three different occasions. This way, you'll really learn the material. The idea is to learn HOW to teach. The NRA course teaches teaching very, very well. Their courses suck in just about any way that's useful for fighting...but they're fine classes for first-timers.
2) Become a tactics and tactical fighting expert. Take a whole bunch of courses. Your shooting should be exceptional. However, the world is "advancing", so you'll need to mix in some combatives, awareness, and knifing (commonly used weapon).
If you cannot deliver on demand, then you will not be able to demonstrate the techniques and you'll lose credibility.
3) Get a reloader and apply a program to your range time. If you are not a great shot, then you need to get several thousand rounds and become a great shot. Dry fire frequently and practice your draw (for pistols).
4) Learn point shooting. Everyone thinks it's all about small groups on a target...fighting is anything but that. It's about scoring hits on the MOVE. Point shooting excels in two areas: speed to first shot and scoring hits while moving. The reason it does so is because human hardwiring forces us to LOOK AT the target (not the sights). Overriding this takes serious dedication and many extra hours of training. Why bother when you can get proficient in a week?
5) Combatives. Get hit. Hit back. Learn some combatives and integrate them into your workouts.
6) Physical fitness. If you're overweight and unfit, you're a loser in the tactics world. Don't be a mall ninja. Be fit, have a flat stomach and be able to fight. If you don't have the discipline to do that, why should anyone listen to you about life saving combat techniques?
7) Be a Range Officer. Get RO certified and volunteer twice a month at the range. Trust me, you'll invest in ballistic armor after a few weeks of that. But, you'll also get essential experience in running a line of shooters. You'll be able to handle yourself while watching the oncoming train wreck :banghead:
Don't expect to make much money unless you have some serious credibility. This is an insanely tough business with a TINY market segment. For all of the NRA's 3-4 million members, it seems like only 10,000 of them are interested in any sort of class. The hardcore guys tend to go two or three times a year, so you're competing for repeat business. Additionally, material is finite and people like to mix it up to get different perspectives (that means "stories" about "seeing the elephant"). You'll see many repeat customers (and get referrals), but don't expect them to come out to your Level 1 course four times and then run through your Level 2 course a bunch of times. Ammo is too expensive for that nowadays.
Just remember: your $150 or $200 course competes with the big name $400-$600 course with the same material. Guess what...they'll pay that $600 too!
Then there's the backstabbing and drama. People get possessive or will try to get you to sign a contract. Don't do it without having an attorney review it!!! Trust me on this...you do NOT want to lose your hard won material because some douchebag claims it in court. All this crap is just about open source anyways; the human hand and eye have not changed since the 40's and gun training started really evolving. Yet, you'll see guys putting their name on anything and everything...AND IT'S THE SAME STUFF! A quick dig through the books of the past will show stuff like...gun lights on gun in the 1930's, point shooting lessons from Ed McGivern, and "zipper" drills straight out of Fairbairn and Sykes (it's inferred from the three point shooting positions described in the manual).