It is very important for us to look to nature for the laws of effortless movement. Nature doesn't try, it just does. Your body is part of that nature.
In a recent development in my teaching I have been encouraging my students to compare their motions when playing and when not playing the guitar. It's a simple awareness exercise to feel if our motion is natural or constricted.
For example, take your right hand and hold it in front of you in a relaxed manner. Now move your fingers rapidly back and forth in the form of an arpeggio pattern - perhaps PAMI. Don't try to move them with large motions, just move them playfully and effortlessly. Is it difficult to do this? Most likely it is not. You'll probably find that it is very easy to move the fingers quickly and fluidly. This is natural motion.
Now take the same arpeggio pattern and perform it on the guitar at the same speed. Do you notice the introduction of tension into the fingers? Do you notice an inner tightening? Do you notice a feeling of "trying" entering into the technique? If so, then this motion is constricted. Don't worry about trying to relax the motion - just feel the constriction fully in the hand and body. Keep going back and forth between the two types of motions - on the guitar, and away from the guitar. Feel the difference between both with great interest.
With time and patience, you'll notice that the body will start to apply the natural motion when playing the guitar. Why? Because the natural motion becomes a clear and penetrating idea. Any clear idea can be learned.
This comparison exercise has become so effective for me, that I now practice about half of my technique on the guitar, and the other half away from the guitar. Every time I feel a restriction in my technique, I check the motion away from the guitar to see and feel the difference. It's amazing to notice the amount of stress we can put into the simplest movements. We create unecessary difficulties this way. Awareness is the key to change.
The body already knows how to move beautifully. We want to study what it does in its natural, effortless state. It's your greatest teacher.