I firmly believe that, with any action we do, when it's as close to the feeling of rest as possible is when the best outcome happens. This is not easy and I find, especially in percussion, that many don't get as close to this point as is actually possible. This is caused by a growing "cultural" need to control the stick to get what you need. While accuracy and consistency are possible with this mindset, the things that suffer are sound variability and physical malleability. If we over control the stick, it cannot rebound freely, hindering its motion and the instrument's response to it. Usually, the trend that tries to counter this is using bigger muscles while having loose hands and this does work. However, this accomplishes one sound and unless something changes, the sound will have the same character, just different volumes.
My instructors were.....crazy. Not only could they navigate the natural rebound of the stick without hindering it, but could control the types of rebounds to get different characters, lifting for bright sounds with the wrist while using arm weight for dynamics and so many other combinations. While some may not even notice these differences, you can definitely tell the difference between one who does do this and one who doesn't. Again, this is not an easy thing to accomplish because you have to be as close to an almost meditative state as possible, or else it doesn't work. Any ounce of tension will be heard, felt and distort the flow of energy in the playing. So controlling your ability to get and stay in this "zone" is crucial to making it habitual.
This, ultimately, is my goal with anything I do and it hasn't failed me yet, but I can't stress enough that it's not easy to do or to accept. Everything is easy; that's the philosophy behind it for me. If everything feels like I'm just walking down the street, that's the feel. Why do yoga? All the crazy poses and they just tell you to do them like it's the most peaceful, no stress, easiest thing ever. The ones who accomplish that are the masters of not only their body but their mind. The perception of the "hard" position is that it's both possible and easy to do. Why not the same for our playing? Why kill yourself playing soft? Just let the soft happen. Let that moment dictate your motions. This is freedom of motion at its best. This is freedom of expression at its greatest! Just rest in it.