The biggest change that helped me in the beginning days of my training to resolve MFD was to shift my mindset from being result oriented to being more in tune with the process of acquiring the results.
After some self analysis and feedback from my closest family and friends, I started noticing my tendency on always being in a hurry to achieve the desired results and not being attentive to what happens in the process. Sometimes the actions of achieving something fast costed me physical and mental stress, but I had a fast paced mind that seem to like the challenges that it brought. I've always learned pieces fairly fast, I memorised music very quickly, I sight read pretty well and could put together a program for a performance pretty fast especially under stress.... or... it sure seemed like it.
I did not like to practice slowly if I didn't have to, because it felt like I could "get by" without practicing slow, and it felt as though it will put off my end results further away since it seemed like it was going to take longer to practice. I learned the hard way and discovered that somehow I missed some crucial awareness that comes hand in hand with slow practice. Later, I found out that this is a pretty common characteristic tendency found among folks with focal dystonia.
Today when I teach students of any level, I advise my students to do exactly the opposite of what my natural tendency was. Practicing slowly is not only effective and efficient, it's pretty much essential.
We need to slow down our thoughts and movements to organically process every bit of difference in position, pressure, speed, touch and contact, vision and sound with the instrument into our memory.
We are processing much more information when we play an instrument than we probably could ever imagine. Amidst all information we gather unconsciously, thoughtful attention is what internalises the conscious leaning process .. Whether you are a fast thinker or not, things does take time to process and what you give attention is what you will retain. It is super important that we are conscious and aware when our bodies and minds that are micro-adjusting to every split second of movement or a thought.
The senses of how the body, arms, hands and fingers are feeling at any given position, angle and touch is very specific to the context of what you're playing and how you are playing. Fine tuning into those senses when you practice slow in particular, will allow your body to have confidence on knowing how you carry out those movements more consistantly and in more immediate variations.
In fact, one of the symptoms of stage freight, not being able to carry those movements during the performance, can be traced back into those practice sessions where you missed out on the information (senses) needed to carry out the movements. In slightly different environment such as your heightened or lowered body awareness during performance, your body all of a sudden realises that it does not know what the process of carrying out those movements are because it has not been ingrained in your memory in the first place. You had skipped that attention during your practice sessions.
I speculate that rapid processing of so many things in not-so-optimal environment (such as stress and tension in your body), forces your body to short cut the process to accommodate everything... and thus when it reaches the data processing status quo, it deletes a whole chunk of what is essential to carry on a movement. I think this is the beginning of focal dystonia symptoms.
Cutting to the point, resolving focal dystonia is like filling in the missing data. As soon as we start inputting the missing awareness, the symptoms start subsiding. It's not as difficult as it sounds!