hey spirit,

Not quite sure the subconcious is something you can improve or practice. You could practice your ability to reach it while awake, though (like through meditation).

I think the subcoucious is just like this big jar that collects all this info that your waking mind can't process. Whether this jar can be modified or improved through somekind of exercise, I'm not sure - I think it's just there. But you can practice taking the lid off of it whenever you want to reach in and have a cookie