Let us reiterate, do not despise practise. Your gestures and movements may be spontaneous and still be wrong. No matter how natural they are, it is possible to improve them.
It is impossible for anyone--even yourself--to criticise your gestures until after they are made. You can't prune a peach tree until it comes up; therefore speak much, and observe your own speech. While you are examining yourself, do not forget to study statuary and paintings to see how the great portrayers of nature have made their subjects express ideas through action. Notice the gestures of the best speakers and actors. Observe the physical expression of life everywhere. The leaves on the tree respond to the slightest breeze.