All good advice. Also keep in mind that it is usually desireable to use the outermost hole on the servo arm to get the maximum leverage from the servo and vary the holes in the horn on the control surface for trim. Because the servo moves in an arc you also get diminishing returns the farther it has to rotate. (towards the end of the rotation it's moving the rod as much sideways as back-and-forth). If you can keep it to 60º, 30º either way, you're in tall cotton.

Anymore I use the outer servo hole (generally on a 20mm/1" servo arm), the next to the last control arm hole and use digital sub-trims and endpoints to get where I'm going.