Hi,
Sometimes I have a student do the pinch method. This can help them relax a bit and does seem to reduce over controling some what.
Proprioception is basically knowing where you body parts are. ( don't think about it to hard you'll get a cramp) The two finger method could help improve this. Some fliers may have a bit of decreased sensation( elderly, diabetics, arthritics, etc) the pinch method could help a lot in these cases.