Another trick: critical direction of surface is a pull. In other words, if you are running up trim, it needs the control horn on top to be a pull for up. Powered models need pull for right rudder, torque will make it turn left using standard rotation. Ailerons need pull for up. Ueah I know that shows the control horns, but you'll thank me later.
If it's a pull, you can get by with string and no stiffening.