As a general practice it is good to set the mechanical linkage so that the servo is allowed to move in it's full range of travel instead of using just a fraction of the servo's full "Travel Volume".
This not only gives the servo maximum mechanical advantage [highest torque rating] but it also prevents you from prematurely wearing out just a few gear teeth that are doing all of the work. You will also enjoy more precise control...but at the expense of slower control surface response.
If you are flying 3D..this tip isn't for you.
I have done range checks to rule out mysterious problems by turning on the system, leave the TX in the pits and then go for a walk with my plane and the engine running. I'm looking for any area of the field where the controls start twitching.