All very good advice, but Evil Twin missed a very important point when referring to
as soon as you tense up you start to manipulate cyclic with your shoulder and everything becomes mechanical and jerky amplifying the secondary effects until it all falls to pieces in a sweaty frustrated mess.
Don't move from the shoulder.
Don't move from the elbow.
Rest your forearm on your thigh and all movements should emanate from the wrist, but essentially with fingers and thumb. You don't control your pen when writing with either your elbow or your shoulder, the same goes for your cyclic.
You are then minimising the number of pivot points in the chain and the subsequent gentle movements will bring a lot of finer control to your flying.