There was an excellent piece by Craig Custance for the Athletic on Leafs Skills Development expert Daryl Belfry who also works with other players in the summer. It is paywalled but for those who have a subscription, definitely worth the read. It is in the form of a Q & A. It delves into the players meeting in the summer and how this summer they broken aspects of their game with each other and how beneficial it was. There is a portion that outlines how he goes about working with these guys and the process. It also heavily focuses on Auston Matthews and how he is not just striving to be a great player, but the best and how he has reinvented his shot again this year.