1) If they stand you stand, if they sit you sit. Be involved, not a spectator. There are already plenty of spectators nearby.
2) Give form advice or motivation at all times. Be moving unless you need to make a big point. If you’ve got nothing to say are you really helping or not?
3) Smile and look like you’re having a good time. You can be tough and smile at the same time, it actually shows your tougher. You enjoy hard work and enjoy being with your client/workout partner. Stop with the serious “I want to crush the world” testosterone facial expression (there’s a place for this, but not when the majority of the people don’t share the same mentality), there’s too many of those people already. A blank expression just shows your mind is someplace else.
4) Walk with, never ahead or behind them. You’re together on this, it isn’t leader-follower or the other way around.
5) Track a lot of data for them, with paper and pencil, and more than they ask for. They’ll thank you down the road when they understand better why they are progressing or falling behind. Track not just the name of the exercise but also:
A) Heart rate before and after each set (use a heart rate monitor or count for 6 seconds and multiply by 10)
B) Load (everyone, sooner or later, wants to know how much load they moved/lifted)
C) Time (count the time from the start of movement to the end, not reps, you can’t be a good coach and count at the same
time and the duration of your set matters more than reps)
D) Rest (be clear on the rest period and track the exact number in seconds, to the exact second)
E) Rate of perceived exertion (RPE, on a scale of 1-10 how hard was that set?)
F) Any thoughts either of you had about the exercise or the set
Do you want your client/workout partner to get the training help/buddy they deserve or not?