Visualise and manifest everything you want to do on a snowboard. Get quite and go inward to understand your mind and your fears. Every high-level athlete has some sort of mental practice, why should you be any different?
Take 5-10 minutes a day to be silent, calm your mind, reframe your fears and reflect on your performance. It's an invaluable skill to be able to breathe and stay calm in any situation. Especially in snowboarding when the consequence can be getting hurt. You could be trying a new skill, learning a brand new trick, ripping fast through the trees or standing on top of a drop. A strong mental game is crucial.
When your mind races and you lose the present moment and disconnect from your body awareness, that's when things can go wrong.