I recently started teaching music through AmeriCorps to K-8th grade kids in rural Oregon. I've been working with praising the process over the result. It's certainly required a mentality shift, but I can see it working with students (especially those who might not grasp a concept as quickly as others).
I've adopted this mentality for myself as well. Growing up, I had never been good at math. I would make mistakes and fall behind in class and wasn't really ever able to catch up. I've recently started learning math again (starting at Algebra I) and have been loving it. Yes I move slow and still make mistakes. But I've been noticing that overcoming those mistakes is one of the most rewarding feelins ever. More than that, it motivates me to continue. I plan to tackle Geometry, Calc, and Physics next.