I recommend that you take all clients through the foundation movements and teach them how to stabilize their “core”. This is all of the movements that the body is capable of at each joint. And how to engage the abdominals, spinal muscles, glutes/hip stabilizers, shoulders/thoracic stabilizers, etc. Initially you would have them do these movements one joint at a time and you should make notes of ROM deficits. Once you have the basics down you can start to combine movements, core stabilizing, and balance training. After a bit of that things really start to get interesting.
If you are not sure about what I am talking about you can contact me through my website www.hawaiifitnessacademy.com . I am willing to help get you started on researching on your own for free. But I do make my living from teaching fitness professionals these types of things. My CEC courses save a lot of time and effort. And my students always leave with a new outlook on our profession and their roll in it.