When setting up a model for a maiden flight, I use the Chip Clip thingees that you put on opened potato chips bags to keep em' fresh. They're cheap, come in a bunch of sizes and hold the control surface in perfect alignment with the flight surface to center your pushrod/clevises. They also come in handy for putting clamping pressure on longer pieces, like when sheeting built-up ailerons.

Two cautions:

1) Always remember to remove the clip(s) BEFORE checking for control surface throw. Otherwise the servos make funny noises but the surfaces don't move... [&:]

2) Only use the clips with the plastic or rubber tubing inside, never the serrated edge kind, for obvious reasons... [:@]

Ed