This is where I normally recommend this video:
https://vimeo.com/ondemand/27507/115504807 
Yup, you have to pay but it is very little, especially compared to what you get. I have watched this video many, many times and my teacher has praised my progress and playing technique many times lately. She is intrigued how much I have improved and to tell the truth, it is not exactly due to practice 8 hours a day, or extensive work with finger exercises ...
He also have some videos for free at the same site about posture.
Also check YouTube for Taubmann technique and Edna Golinsky. She talks a lot about wrist rolling movements, it is worth a try - I don't think her technique is suitable for everyone, but it is very good for some.
You will be surprised what impact "detail work" can have. Far too many of us believe piano playing is about whacking our way through tons of pieces, the faster the better, then add countless hours of playing scales and Hanon or whatever you think is good, to and fro, up and down, like an athlete doing his daily workout. But technical exercises do not have to be about playing fast, faster, fastest all the time, like a sewing machine, pretending you are good because you are doing something DIFFICULT.